diff --git a/.aws-sam/build.toml b/.aws-sam/build.toml
new file mode 100644
index 0000000..ed5d88e
--- /dev/null
+++ b/.aws-sam/build.toml
@@ -0,0 +1,15 @@
+# This file is auto generated by SAM CLI build command
+
+[function_build_definitions.59b4df2e-a009-469c-8bf5-d19de268fe1d]
+codeuri = "/home/runner/work/lambda-opentelemetry-demo/lambda-opentelemetry-demo"
+runtime = "nodejs20.x"
+architecture = "x86_64"
+handler = "src/order-service/index.handler"
+manifest_hash = ""
+packagetype = "Zip"
+functions = ["OrderServiceFunction", "InventoryServiceFunction", "PaymentServiceFunction"]
+
+[function_build_definitions.59b4df2e-a009-469c-8bf5-d19de268fe1d.metadata]
+BuildMethod = "nodejs20.x"
+
+[layer_build_definitions]
diff --git a/.aws-sam/build/InventoryServiceFunction/.env.example b/.aws-sam/build/InventoryServiceFunction/.env.example
new file mode 100644
index 0000000..3f3aa74
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/.env.example
@@ -0,0 +1,7 @@
+# OpenTelemetry Configuration
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318/v1/traces
+ENVIRONMENT=development
+
+# Service URLs (for local testing)
+INVENTORY_SERVICE_URL=http://localhost:3001/inventory
+PAYMENT_SERVICE_URL=http://localhost:3002/payment
diff --git a/.aws-sam/build/InventoryServiceFunction/ADOT-LAYER-CONFIG.md b/.aws-sam/build/InventoryServiceFunction/ADOT-LAYER-CONFIG.md
new file mode 100644
index 0000000..cffddc9
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/ADOT-LAYER-CONFIG.md
@@ -0,0 +1,366 @@
+# AWS ADOT Lambda Layer Configuration Guide
+
+This document explains how to configure and use the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for automatic instrumentation.
+
+## Overview
+
+The AWS ADOT Lambda Layer provides automatic OpenTelemetry instrumentation for Lambda functions without requiring you to bundle OpenTelemetry SDKs in your deployment package.
+
+## Layer ARNs by Region
+
+### Node.js 18.x ADOT Layer ARNs (Latest: v1-18-1)
+
+| Region | ARN |
+|--------|-----|
+| us-east-1 | `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-east-2 | `arn:aws:lambda:us-east-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-1 | `arn:aws:lambda:us-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-2 | `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-west-1 | `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-central-1 | `arn:aws:lambda:eu-central-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-southeast-1 | `arn:aws:lambda:ap-southeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-northeast-1 | `arn:aws:lambda:ap-northeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+
+**Find the latest ARNs**: https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+## Required Environment Variables
+
+### Essential Configuration
+
+```yaml
+Environment:
+  Variables:
+    # Enable ADOT auto-instrumentation wrapper
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+    
+    # Service name for identification in traces
+    OTEL_SERVICE_NAME: your-service-name
+    
+    # Sampling configuration (AlwaysOn for demo, adjust for production)
+    OTEL_TRACES_SAMPLER: AlwaysOn
+    
+    # Protocol for OTLP export
+    OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+    
+    # OpenTelemetry Collector endpoint (without /v1/traces)
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://your-collector:4318
+    
+    # Trace context propagation format
+    OTEL_PROPAGATORS: tracecontext
+```
+
+### Advanced Configuration Options
+
+```yaml
+Environment:
+  Variables:
+    # Resource attributes (for environment, version, etc.)
+    OTEL_RESOURCE_ATTRIBUTES: deployment.environment=production,service.version=1.0.0
+    
+    # Specific endpoint for traces (optional, overrides OTEL_EXPORTER_OTLP_ENDPOINT)
+    OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: http://your-collector:4318/v1/traces
+    
+    # Enable/disable specific instrumentations
+    OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: true
+    OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+    
+    # Span attribute limits
+    OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT: 4095
+    OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 128
+```
+
+## Exporter Backends
+
+### 1. Jaeger (Local Development)
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://localhost:4318
+OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+```
+
+Run Jaeger with OTLP support:
+```bash
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+```
+
+### 2. AWS X-Ray (with ADOT Collector)
+
+If you want to send traces to AWS X-Ray, deploy an ADOT Collector in your VPC:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://adot-collector:4318
+OTEL_PROPAGATORS: tracecontext,xray
+```
+
+ADOT Collector configuration:
+```yaml
+receivers:
+  otlp:
+    protocols:
+      http:
+        endpoint: 0.0.0.0:4318
+
+exporters:
+  awsxray:
+    region: us-east-1
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      exporters: [awsxray]
+```
+
+### 3. Grafana Cloud / Honeycomb / DataDog
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: https://your-saas-endpoint
+OTEL_EXPORTER_OTLP_HEADERS: Authorization=Bearer your-api-key
+```
+
+### 4. Self-Hosted OpenTelemetry Collector
+
+Deploy a collector in your VPC or use Lambda Extension:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+## How Auto-Instrumentation Works
+
+### 1. Wrapper Execution
+
+The `AWS_LAMBDA_EXEC_WRAPPER` environment variable points to `/opt/otel-handler`, which:
+- Initializes the OpenTelemetry SDK before your handler
+- Automatically instruments common libraries (http, https, aws-sdk, etc.)
+- Creates a root span for each Lambda invocation
+- Propagates trace context from incoming requests
+
+### 2. Automatic Instrumentation
+
+The layer automatically instruments:
+- ✅ AWS SDK calls
+- ✅ HTTP/HTTPS requests (axios, node-fetch, http, https)
+- ✅ Lambda invocation (creates root span)
+- ✅ Downstream service calls with trace context propagation
+
+### 3. Context Propagation
+
+The layer automatically:
+- Extracts W3C trace context from incoming API Gateway requests
+- Injects trace context into outgoing HTTP requests
+- Maintains trace context across async operations
+
+## Usage in Your Code
+
+### Basic Usage (Automatic)
+
+With the layer configured, your Lambda function is automatically instrumented:
+
+```javascript
+exports.handler = async (event) => {
+  // Automatically traced!
+  const response = await axios.get('https://api.example.com');
+  return { statusCode: 200, body: JSON.stringify(response.data) };
+};
+```
+
+### Adding Custom Spans
+
+For additional business logic spans:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service', '1.0.0');
+  
+  return tracer.startActiveSpan('business-operation', async (span) => {
+    try {
+      span.setAttribute('customer.id', event.customerId);
+      
+      // Your business logic
+      const result = await processOrder(event);
+      
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.recordException(error);
+      span.setStatus({ code: api.SpanStatusCode.ERROR });
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+};
+```
+
+### Adding Attributes to Current Span
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const span = api.trace.getActiveSpan();
+  if (span) {
+    span.setAttribute('order.id', event.orderId);
+    span.setAttribute('order.amount', event.amount);
+  }
+  
+  // Your handler logic
+};
+```
+
+## Trace Context Propagation
+
+### Automatic (HTTP Clients)
+
+The layer automatically propagates context for instrumented HTTP clients:
+
+```javascript
+const axios = require('axios');
+
+// Trace context is automatically added to headers!
+const response = await axios.post('https://api.example.com/payment', data);
+```
+
+### Manual (Custom Clients)
+
+For custom HTTP clients or non-instrumented libraries:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+function getTraceHeaders() {
+  const headers = {};
+  const span = api.trace.getActiveSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-01`;
+  }
+  
+  return headers;
+}
+
+// Use in your custom client
+const headers = { ...getTraceHeaders(), 'Content-Type': 'application/json' };
+```
+
+## Sampling
+
+### AlwaysOn (Development/Demo)
+
+```yaml
+OTEL_TRACES_SAMPLER: AlwaysOn
+```
+
+Traces every request. Good for development but expensive in production.
+
+### TraceIdRatioBased (Production)
+
+```yaml
+OTEL_TRACES_SAMPLER: TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1  # 10% sampling
+```
+
+Samples a percentage of requests to reduce costs.
+
+### ParentBased (Recommended)
+
+```yaml
+OTEL_TRACES_SAMPLER: ParentBased_TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1
+```
+
+Respects parent sampling decisions while applying ratio-based sampling to root spans.
+
+## Performance Considerations
+
+### Cold Start Impact
+
+The ADOT layer adds ~200-300ms to cold start time:
+- Layer initialization: ~100ms
+- Auto-instrumentation setup: ~100-200ms
+
+### Runtime Overhead
+
+- Minimal overhead during warm execution (<5ms per invocation)
+- Async span export doesn't block Lambda execution
+- Batching reduces network calls
+
+### Optimization Tips
+
+1. **Use provisioned concurrency** for latency-sensitive functions
+2. **Adjust span limits** to reduce memory usage:
+   ```yaml
+   OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 32
+   OTEL_SPAN_EVENT_COUNT_LIMIT: 32
+   ```
+3. **Use sampling** in high-volume environments
+4. **Disable unused instrumentations**:
+   ```yaml
+   OTEL_INSTRUMENTATION_AWS_LAMBDA_ENABLED: true
+   OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+   OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: false
+   ```
+
+## Troubleshooting
+
+### No Traces Appearing
+
+1. Check CloudWatch Logs for ADOT errors:
+   ```
+   grep "otel" /aws/lambda/your-function
+   ```
+
+2. Verify environment variables:
+   ```bash
+   aws lambda get-function-configuration --function-name your-function \
+     --query 'Environment.Variables'
+   ```
+
+3. Test collector endpoint connectivity:
+   - Ensure Lambda has network access to the collector
+   - Check security groups and NACLs
+   - Verify collector is accepting OTLP HTTP on port 4318
+
+### Wrapper Not Running
+
+Error: `AWS_LAMBDA_EXEC_WRAPPER is set but the wrapper does not exist`
+
+**Solution**: Verify the layer ARN is correct and matches your region.
+
+### Trace Context Not Propagating
+
+1. Ensure `OTEL_PROPAGATORS=tracecontext` is set
+2. Check if HTTP library is supported (axios, node-fetch, http, https)
+3. For unsupported libraries, manually inject headers
+
+### High Cold Start Times
+
+1. Consider using Lambda SnapStart (if available)
+2. Use provisioned concurrency
+3. Minimize layer count (combine layers if possible)
+4. Profile and optimize your application code
+
+## Best Practices
+
+1. **Set meaningful service names**: Use descriptive names that reflect the business function
+2. **Add business context**: Include order IDs, customer IDs, and other relevant attributes
+3. **Handle errors properly**: Record exceptions and set error status on spans
+4. **Use semantic conventions**: Follow OpenTelemetry semantic conventions for consistency
+5. **Monitor collector health**: Ensure your collector is performant and highly available
+6. **Set appropriate sampling**: Balance cost with observability needs
+7. **Use tags for filtering**: Add environment, version, and region as resource attributes
+
+## References
+
+- AWS ADOT Lambda: https://aws-otel.github.io/docs/getting-started/lambda
+- OpenTelemetry Lambda Instrumentation: https://opentelemetry.io/docs/platforms/faas/lambda-auto-instrument/
+- W3C Trace Context: https://www.w3.org/TR/trace-context/
+- OpenTelemetry Semantic Conventions: https://opentelemetry.io/docs/specs/semconv/
diff --git a/.aws-sam/build/InventoryServiceFunction/ARCHITECTURE.md b/.aws-sam/build/InventoryServiceFunction/ARCHITECTURE.md
new file mode 100644
index 0000000..ff7e7c2
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/ARCHITECTURE.md
@@ -0,0 +1,366 @@
+# Architecture Details
+
+## Service Flow
+
+### 1. Successful Order Flow
+
+```
+Client
+  │
+  │ POST /order
+  ├─────────────────────────────────────────┐
+  │                                         │
+  ▼                                         │
+Order Service                               │
+  │                                         │
+  │ 1. Validate request                     │
+  │ 2. Create root span                     │
+  │                                         │
+  │ POST /inventory (with trace context)    │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Inventory Service               │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Check stock levels       │           │
+  │ 4. Return availability      │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: available=true    │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ POST /payment (with trace context)      │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Payment Service                 │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Process payment          │           │
+  │ 4. Return result            │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: success=true      │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ Complete order processing   │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: 200 OK            │           │
+  ▼                             │           │
+Client ◄──────────────────────────────────────┘
+```
+
+### 2. Out of Stock Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Out of stock detected)
+                       ← 
+         Order Service 
+         (Skip payment, return 409)
+       ←
+Client
+```
+
+### 3. Payment Failure Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Items available)
+                       ← 
+         Order Service → Payment Service
+                         (Payment failed)
+                       ←
+         Order Service
+         (Return 402)
+       ←
+Client
+```
+
+## Trace Structure
+
+### Trace Hierarchy
+
+```
+Trace ID: 00000000000000000000000000000001
+│
+└─ Span: process-order (Order Service)
+   │ Duration: 245ms
+   │ Attributes:
+   │   - order.id: ORD-001
+   │   - customer.id: CUST-123
+   │   - order.items.count: 2
+   │
+   ├─ Span: check-inventory (Order Service)
+   │  │ Duration: 15ms
+   │  │ Attributes:
+   │  │   - service: inventory
+   │  │   - order.id: ORD-001
+   │  │
+   │  └─ Span: HTTP POST (Auto-instrumented)
+   │     │ Duration: 12ms
+   │     │
+   │     └─ Span: check-inventory (Inventory Service)
+   │        Duration: 8ms
+   │        Attributes:
+   │          - inventory.available: true
+   │          - inventory.items.count: 2
+   │
+   └─ Span: process-payment (Order Service)
+      │ Duration: 180ms
+      │ Attributes:
+      │   - service: payment
+      │   - order.id: ORD-001
+      │   - payment.method: credit-card-5555
+      │   - payment.amount: 1059.97
+      │
+      └─ Span: HTTP POST (Auto-instrumented)
+         │ Duration: 175ms
+         │
+         └─ Span: process-payment (Payment Service)
+            Duration: 170ms
+            Attributes:
+              - payment.success: true
+              - payment.transaction_id: txn-1234567890-abc123
+```
+
+## OpenTelemetry Components
+
+### 1. Tracer Provider
+
+Manages the lifecycle of tracers and span processors.
+
+```javascript
+const provider = new NodeTracerProvider({
+  resource: resource,
+});
+```
+
+### 2. OTLP Exporter
+
+Exports spans to OpenTelemetry Collector using HTTP.
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: 'http://localhost:4318/v1/traces',
+});
+```
+
+### 3. Batch Span Processor
+
+Batches spans before export for efficiency.
+
+```javascript
+provider.addSpanProcessor(new BatchSpanProcessor(exporter));
+```
+
+### 4. Auto Instrumentations
+
+Automatically instruments common libraries.
+
+```javascript
+registerInstrumentations({
+  instrumentations: [
+    getNodeAutoInstrumentations({
+      '@opentelemetry/instrumentation-http': { enabled: true },
+      '@opentelemetry/instrumentation-https': { enabled: true },
+    }),
+  ],
+});
+```
+
+## Trace Context Propagation
+
+### W3C Trace Context Format
+
+```
+traceparent: 00-<trace-id>-<span-id>-<trace-flags>
+
+Example:
+traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+            │  │                                │                │
+            │  └─ Trace ID (32 hex chars)      │                └─ Flags
+            │                                   └─ Parent Span ID (16 hex chars)
+            └─ Version (00)
+```
+
+### Context Injection
+
+When Order Service calls Inventory Service:
+
+```javascript
+// Order Service
+const headers = injectTraceContext();
+// headers = { traceparent: '00-...-...-01' }
+
+axios.post(inventoryUrl, data, { headers });
+```
+
+### Context Extraction
+
+When Inventory Service receives request:
+
+```javascript
+// Inventory Service
+const traceContext = extractTraceContext(event);
+// Continue the trace with the same trace ID
+```
+
+## Span Attributes
+
+### Semantic Conventions
+
+Following OpenTelemetry semantic conventions:
+
+| Attribute | Description | Example |
+|-----------|-------------|---------|
+| `service.name` | Service identifier | `order-service` |
+| `service.version` | Service version | `1.0.0` |
+| `deployment.environment` | Environment | `production` |
+| `order.id` | Order identifier | `ORD-001` |
+| `customer.id` | Customer identifier | `CUST-123` |
+| `payment.amount` | Payment amount | `1059.97` |
+| `payment.method` | Payment method | `credit-card-5555` |
+| `inventory.available` | Availability flag | `true` |
+| `http.method` | HTTP method | `POST` |
+| `http.status_code` | HTTP status | `200` |
+
+## Error Handling
+
+### Error Span Status
+
+```javascript
+span.setStatus({
+  code: api.SpanStatusCode.ERROR,
+  message: error.message,
+});
+span.recordException(error);
+```
+
+### Business Logic Errors vs Technical Errors
+
+- **Business Logic Errors** (out of stock, payment declined):
+  - Span status: OK
+  - Custom attributes indicate business failure
+  - Example: `inventory.available: false`
+
+- **Technical Errors** (network failure, invalid input):
+  - Span status: ERROR
+  - Exception recorded
+  - Stack trace captured
+
+## Performance Considerations
+
+### Batch Processing
+
+Spans are batched before export to reduce network overhead:
+
+```javascript
+new BatchSpanProcessor(exporter, {
+  maxQueueSize: 2048,
+  maxExportBatchSize: 512,
+  scheduledDelayMillis: 5000,
+})
+```
+
+### Sampling
+
+For high-volume systems, implement sampling:
+
+```javascript
+const sampler = new TraceIdRatioBasedSampler(0.1); // 10% sampling
+const provider = new NodeTracerProvider({
+  resource: resource,
+  sampler: sampler,
+});
+```
+
+### Async Export
+
+Span export is asynchronous and doesn't block Lambda execution.
+
+## Security
+
+### Securing OTLP Endpoint
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
+  headers: {
+    'Authorization': `Bearer ${process.env.OTEL_API_KEY}`,
+  },
+});
+```
+
+### Data Privacy
+
+- Avoid capturing sensitive data in spans
+- Redact PII from span attributes
+- Use attribute filtering in the collector
+
+## Monitoring and Alerting
+
+### Key Metrics to Monitor
+
+1. **Trace Completeness**
+   - Percentage of complete traces
+   - Missing spans
+
+2. **Error Rates**
+   - Spans with ERROR status
+   - Service-specific error rates
+
+3. **Latency**
+   - P50, P95, P99 latencies
+   - Per-service latency breakdown
+
+4. **Business Metrics**
+   - Order success rate
+   - Payment failure rate
+   - Inventory unavailability rate
+
+### Example Queries (Jaeger)
+
+```
+# Find all failed orders
+service="order-service" AND error=true
+
+# Find orders with payment failures
+service="payment-service" AND payment.success=false
+
+# Find slow orders (> 1s)
+service="order-service" AND duration>1000ms
+
+# Find out-of-stock scenarios
+service="inventory-service" AND inventory.available=false
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Traces not appearing**
+   - Check OTLP endpoint connectivity
+   - Verify Lambda has network access
+   - Check CloudWatch logs for export errors
+
+2. **Broken traces**
+   - Verify trace context propagation
+   - Check HTTP header forwarding
+   - Ensure consistent trace ID format
+
+3. **High latency**
+   - Review span processor configuration
+   - Check collector performance
+   - Consider async export optimization
+
+4. **Missing spans**
+   - Verify auto-instrumentation is active
+   - Check for exceptions during span creation
+   - Review sampling configuration
diff --git a/.aws-sam/build/InventoryServiceFunction/README.md b/.aws-sam/build/InventoryServiceFunction/README.md
new file mode 100644
index 0000000..aff152d
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/README.md
@@ -0,0 +1,476 @@
+# Lambda OpenTelemetry Demo
+
+A comprehensive AWS Lambda project demonstrating how to integrate OpenTelemetry for end-to-end distributed tracing across multiple microservices **without using AWS CloudWatch or X-Ray**, using the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation.
+
+## 🎯 Overview
+
+This project implements a realistic e-commerce order processing workflow using three Lambda functions representing distinct microservices:
+
+1. **Order Service** - Orchestrates the order processing workflow
+2. **Inventory Service** - Validates item availability
+3. **Payment Service** - Processes payments
+
+The services communicate with each other while propagating trace context using OpenTelemetry, enabling complete visibility into request flows across all services.
+
+## 🏗️ Architecture
+
+```
+┌─────────────────┐
+│  Order Service  │
+│   (Lambda)      │
+└────────┬────────┘
+         │
+         ├──────────────────┐
+         │                  │
+         ▼                  ▼
+┌─────────────────┐  ┌─────────────────┐
+│ Inventory Svc   │  │  Payment Svc    │
+│   (Lambda)      │  │   (Lambda)      │
+└─────────────────┘  └─────────────────┘
+         │                  │
+         └──────┬───────────┘
+                ▼
+        OpenTelemetry
+         Collector
+                │
+                ▼
+        Tracing Backend
+      (Jaeger/Zipkin/etc)
+```
+
+## ✨ Features
+
+- ✅ **AWS ADOT Lambda Layer** - Uses AWS Distro for OpenTelemetry Lambda Layer for zero-code instrumentation
+- ✅ **Automatic Instrumentation** - Auto-instruments Lambda, HTTP/HTTPS, and AWS SDK without code changes
+- ✅ **Distributed Tracing** - End-to-end trace propagation across Lambda functions
+- ✅ **W3C Trace Context** - Standard trace context propagation using W3C format
+- ✅ **OTLP Export** - Exports traces using OTLP HTTP protocol
+- ✅ **Custom Spans** - Manual span creation for business logic insights
+- ✅ **No CloudWatch/X-Ray** - Direct export to any OpenTelemetry-compatible backend
+- ✅ **Error Scenarios** - Built-in test scenarios for:
+  - Out of stock items
+  - Payment failures (card declined, insufficient funds)
+  - Network errors
+
+## 📋 Prerequisites
+
+- Node.js 18.x or later
+- AWS CLI configured with appropriate credentials
+- AWS SAM CLI for deployment
+- OpenTelemetry Collector or compatible backend (Jaeger, Zipkin, etc.)
+
+## 🚀 Quick Start
+
+### 1. Install Dependencies
+
+```bash
+npm install
+```
+
+### 2. Set Up OpenTelemetry Backend
+
+You need an OpenTelemetry-compatible backend to receive and visualize traces. Here are some options:
+
+#### Option A: Jaeger (Recommended for local testing)
+
+```bash
+# Run Jaeger all-in-one with Docker (or use docker-compose)
+docker-compose up -d jaeger
+
+# Or manually:
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+
+# Access Jaeger UI at http://localhost:16686
+```
+
+#### Option B: Zipkin
+
+```bash
+# Run Zipkin with Docker
+docker run -d --name zipkin \
+  -p 9411:9411 \
+  openzipkin/zipkin:latest
+
+# Note: You'll need an OpenTelemetry Collector to convert OTLP to Zipkin format
+```
+
+#### Option C: Grafana Cloud, Honeycomb, or other SaaS providers
+
+Configure the OTEL_EXPORTER_OTLP_ENDPOINT parameter with your provider's endpoint.
+
+### 3. Update Lambda Layer ARN
+
+**Important**: Update the `AdotLayerArn` parameter in `template.yaml` with the correct ARN for your AWS region.
+
+Find the latest ARN for your region here:
+- https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Example ARNs:
+- **us-east-1**: `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **us-west-2**: `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **eu-west-1**: `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+
+See [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md) for complete list.
+
+### 4. Deploy to AWS
+
+```bash
+# Build the Lambda functions
+sam build
+
+# Deploy (follow the prompts)
+sam deploy --guided
+
+# Note the API endpoint from the outputs
+```
+
+During `sam deploy --guided`, you'll be prompted to provide:
+- **Stack name** (e.g., `lambda-otel-demo`)
+- **AWS Region** (e.g., `us-east-1`)
+- **OtelCollectorEndpoint** - Your OpenTelemetry Collector endpoint without `/v1/traces` (e.g., `http://your-collector:4318`)
+- **Environment** - Deployment environment (e.g., `production`, `staging`)
+- **AdotLayerArn** - AWS ADOT Lambda Layer ARN for your region
+- Confirm changes before deployment
+
+**Note**: If you're using a collector in a VPC, ensure your Lambda functions have VPC access configured.
+
+### 5. Test the Services
+
+Use the provided test script:
+
+```bash
+# Replace with your actual API endpoint from SAM deploy output
+./test-api.sh https://your-api-id.execute-api.region.amazonaws.com/Prod
+```
+
+Or manually test with curl:
+
+```bash
+# Successful order
+curl -X POST https://your-api-endpoint/Prod/order \
+  -H "Content-Type: application/json" \
+  -d @test-payloads.json
+```
+
+### 6. View Traces
+
+Open your tracing backend UI:
+- Jaeger: http://localhost:16686
+- Select service: `order-service`
+- Click "Find Traces" to view the end-to-end traces
+
+## 🔧 AWS ADOT Lambda Layer
+
+This project uses the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation. The layer provides:
+
+### Key Benefits
+
+1. **Zero-Code Instrumentation** - Auto-instruments your Lambda function without code changes
+2. **No Dependency Bundling** - OpenTelemetry SDKs are provided by the layer, reducing deployment package size
+3. **Automatic Context Propagation** - Trace context is automatically propagated across service calls
+4. **AWS-Optimized** - Maintained and supported by AWS with regular updates
+
+### How It Works
+
+The layer works through the `AWS_LAMBDA_EXEC_WRAPPER` environment variable:
+
+```yaml
+Environment:
+  Variables:
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler  # Enables auto-instrumentation
+    OTEL_SERVICE_NAME: order-service              # Service identifier
+    OTEL_TRACES_SAMPLER: AlwaysOn                 # Sampling strategy
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+When your Lambda function is invoked:
+1. The wrapper initializes OpenTelemetry SDK
+2. Auto-instrumentation is activated for HTTP, AWS SDK, and Lambda runtime
+3. A root span is created for the Lambda invocation
+4. Your handler executes within the trace context
+5. Spans are exported to your configured OTLP endpoint
+
+### What Gets Instrumented Automatically
+
+- ✅ Lambda function invocations
+- ✅ HTTP/HTTPS requests (axios, node-fetch, native http/https)
+- ✅ AWS SDK v2 and v3 calls
+- ✅ Database clients (when using instrumented libraries)
+- ✅ Trace context propagation in headers
+
+### Adding Custom Instrumentation
+
+While the layer handles most instrumentation automatically, you can add custom spans for business logic:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service');
+  
+  return tracer.startActiveSpan('custom-operation', async (span) => {
+    span.setAttribute('business.attribute', 'value');
+    // Your logic here
+    span.end();
+  });
+};
+```
+
+For detailed configuration options, see [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md).
+
+## 📝 Test Scenarios
+
+### Scenario 1: Successful Order ✅
+
+Tests the happy path where all services succeed.
+
+```json
+{
+  "orderId": "ORD-001",
+  "customerId": "CUST-123",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-001",
+      "name": "Laptop",
+      "quantity": 1,
+      "price": 999.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Success)
+- Order completed with HTTP 200
+
+### Scenario 2: Out of Stock ⚠️
+
+Tests inventory unavailability.
+
+```json
+{
+  "orderId": "ORD-002",
+  "customerId": "CUST-456",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-003",
+      "name": "Keyboard",
+      "quantity": 1,
+      "price": 79.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Out of stock detected)
+- Payment Service NOT called
+- Order fails with HTTP 409
+
+**Out of Stock Items:**
+- `item-003` - Keyboard (0 in stock)
+- `item-005` - Headphones (0 in stock)
+
+### Scenario 3: Payment Failure 💳
+
+Tests payment processing failures.
+
+**Card Declined:**
+```json
+{
+  "orderId": "ORD-003",
+  "customerId": "CUST-789",
+  "paymentMethod": "4111111111111111",
+  "items": [{"itemId": "item-001", "quantity": 1, "price": 999.99}]
+}
+```
+
+**Insufficient Funds:**
+```json
+{
+  "orderId": "ORD-004",
+  "customerId": "CUST-999",
+  "paymentMethod": "4222222222222222",
+  "items": [{"itemId": "item-004", "quantity": 2, "price": 399.99}]
+}
+```
+
+**Test Payment Methods:**
+- `4111111111111111` - Card declined
+- `4222222222222222` - Insufficient funds
+- `4333333333333333` - Expired card
+- Any other value - Success (with 10% random failure rate)
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Payment fails)
+- Order fails with HTTP 402
+
+## 🔍 Understanding the Traces
+
+Each trace will show:
+
+1. **Span Attributes:**
+   - Order ID, Customer ID
+   - Item counts and details
+   - Payment amounts and methods
+   - Service names and versions
+   - Success/failure reasons
+
+2. **Span Hierarchy:**
+   ```
+   process-order (Order Service)
+   ├── check-inventory (Order Service -> Inventory Service)
+   │   └── check-inventory (Inventory Service)
+   └── process-payment (Order Service -> Payment Service)
+       └── process-payment (Payment Service)
+   ```
+
+3. **Trace Context Propagation:**
+   - Trace IDs are consistent across all services
+   - Parent-child relationships are maintained
+   - W3C traceparent headers are used
+
+## 🛠️ Configuration
+
+### Environment Variables
+
+Configure these in the SAM template or Lambda console:
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT` - OpenTelemetry Collector endpoint (default: `http://localhost:4318/v1/traces`)
+- `ENVIRONMENT` - Deployment environment (default: `development`)
+- `INVENTORY_SERVICE_URL` - Inventory service endpoint
+- `PAYMENT_SERVICE_URL` - Payment service endpoint
+
+### Inventory Configuration
+
+Modify the mock inventory in `src/inventory-service/index.js`:
+
+```javascript
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  // Add more items...
+};
+```
+
+### Payment Configuration
+
+Modify failure patterns in `src/payment-service/index.js`:
+
+```javascript
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  // Add more patterns...
+};
+```
+
+## 📂 Project Structure
+
+```
+lambda-opentelemetry-demo/
+├── src/
+│   ├── order-service/          # Order orchestration service
+│   │   └── index.js
+│   ├── inventory-service/      # Inventory check service
+│   │   └── index.js
+│   ├── payment-service/        # Payment processing service
+│   │   └── index.js
+│   └── shared/                 # Shared utilities
+│       ├── tracer.js           # OpenTelemetry setup
+│       └── utils.js            # Common utilities
+├── template.yaml               # AWS SAM template
+├── package.json                # Node.js dependencies
+├── test-payloads.json          # Sample test data
+├── test-api.sh                 # API test script
+└── README.md                   # This file
+```
+
+## 🔧 Local Development
+
+To test locally without deploying to AWS:
+
+1. Start your OpenTelemetry backend (e.g., Jaeger)
+2. Use AWS SAM Local:
+
+```bash
+sam build
+sam local start-api --env-vars env.json
+```
+
+Create `env.json`:
+```json
+{
+  "Parameters": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "INVENTORY_SERVICE_URL": "http://host.docker.internal:3000/inventory",
+    "PAYMENT_SERVICE_URL": "http://host.docker.internal:3000/payment"
+  }
+}
+```
+
+## 📊 Observability Best Practices
+
+This demo demonstrates several observability best practices:
+
+1. **Structured Logging** - Logs include trace context for correlation
+2. **Semantic Attributes** - Meaningful span attributes for filtering and analysis
+3. **Error Handling** - Errors are captured as span events
+4. **Business Context** - Business-relevant data in spans (order IDs, amounts, etc.)
+5. **Service Naming** - Clear service names for easy identification
+6. **Context Propagation** - W3C standard trace context across service boundaries
+
+## 🔐 Security Considerations
+
+- This is a demo project - do not use in production without proper security hardening
+- Implement proper authentication/authorization for API endpoints
+- Secure OpenTelemetry Collector endpoints
+- Use AWS Secrets Manager for sensitive configuration
+- Enable API Gateway throttling and request validation
+
+## 🤝 Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+## 📄 License
+
+MIT License - See LICENSE file for details
+
+## 🎓 Learning Resources
+
+- [OpenTelemetry Documentation](https://opentelemetry.io/docs/)
+- [AWS Lambda Best Practices](https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html)
+- [W3C Trace Context](https://www.w3.org/TR/trace-context/)
+- [Distributed Tracing Guide](https://opentelemetry.io/docs/concepts/signals/traces/)
+
+## 🐛 Troubleshooting
+
+### Traces not appearing in backend
+
+- Verify OTEL_EXPORTER_OTLP_ENDPOINT is correctly configured
+- Check Lambda logs in CloudWatch for errors
+- Ensure OpenTelemetry Collector/backend is running and accessible
+- Verify network connectivity between Lambda and collector
+
+### Service-to-service calls failing
+
+- Check that service URLs are correctly configured
+- Verify API Gateway endpoints are deployed
+- Review Lambda function logs for errors
+- Check IAM permissions if using private endpoints
+
+### High latency or timeouts
+
+- Increase Lambda timeout in template.yaml
+- Check OpenTelemetry Collector performance
+- Consider using asynchronous export
+- Review batch span processor configuration
diff --git a/.aws-sam/build/InventoryServiceFunction/docker-compose.yaml b/.aws-sam/build/InventoryServiceFunction/docker-compose.yaml
new file mode 100644
index 0000000..7f969f4
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/docker-compose.yaml
@@ -0,0 +1,37 @@
+version: '3.8'
+
+services:
+  # Jaeger all-in-one with OTLP support
+  jaeger:
+    image: jaegertracing/all-in-one:latest
+    container_name: jaeger-otel
+    environment:
+      - COLLECTOR_OTLP_ENABLED=true
+      - LOG_LEVEL=debug
+    ports:
+      - "16686:16686"  # Jaeger UI
+      - "4318:4318"    # OTLP HTTP receiver
+      - "4317:4317"    # OTLP gRPC receiver
+      - "14268:14268"  # Jaeger collector HTTP
+      - "14250:14250"  # Jaeger collector gRPC
+    networks:
+      - otel-demo
+
+  # Optional: OpenTelemetry Collector (if you want to use a separate collector)
+  # otel-collector:
+  #   image: otel/opentelemetry-collector-contrib:latest
+  #   container_name: otel-collector
+  #   command: ["--config=/etc/otel-collector-config.yaml"]
+  #   volumes:
+  #     - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+  #   ports:
+  #     - "4318:4318"    # OTLP HTTP receiver
+  #     - "4317:4317"    # OTLP gRPC receiver
+  #     - "8888:8888"    # Prometheus metrics
+  #     - "13133:13133"  # Health check
+  #   networks:
+  #     - otel-demo
+
+networks:
+  otel-demo:
+    driver: bridge
diff --git a/.aws-sam/build/InventoryServiceFunction/env.json b/.aws-sam/build/InventoryServiceFunction/env.json
new file mode 100644
index 0000000..67b70e4
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/env.json
@@ -0,0 +1,16 @@
+{
+  "OrderServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local",
+    "INVENTORY_SERVICE_URL": "http://127.0.0.1:3001/inventory",
+    "PAYMENT_SERVICE_URL": "http://127.0.0.1:3002/payment"
+  },
+  "InventoryServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  },
+  "PaymentServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  }
+}
diff --git a/.aws-sam/build/InventoryServiceFunction/local-test.sh b/.aws-sam/build/InventoryServiceFunction/local-test.sh
new file mode 100755
index 0000000..8b43c30
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/local-test.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Simple local testing script using SAM Local
+# This script starts SAM local API and runs tests
+
+set -e
+
+echo "Starting Lambda OpenTelemetry Demo Local Test"
+echo "=============================================="
+echo ""
+
+# Check if Docker is running
+if ! docker info > /dev/null 2>&1; then
+    echo "Error: Docker is not running. Please start Docker first."
+    exit 1
+fi
+
+# Check if Jaeger is running
+if ! docker ps | grep -q jaeger-otel; then
+    echo "Starting Jaeger..."
+    docker-compose up -d jaeger
+    echo "Waiting for Jaeger to be ready..."
+    sleep 5
+else
+    echo "Jaeger is already running"
+fi
+
+echo ""
+echo "Jaeger UI available at: http://localhost:16686"
+echo ""
+
+# Build the Lambda functions
+echo "Building Lambda functions..."
+sam build
+
+if [ $? -ne 0 ]; then
+    echo "Error: Build failed"
+    exit 1
+fi
+
+echo ""
+echo "Lambda functions built successfully!"
+echo ""
+echo "To test the API:"
+echo "1. Start SAM local API in one terminal:"
+echo "   sam local start-api --env-vars env.json"
+echo ""
+echo "2. In another terminal, run the test script:"
+echo "   ./test-api.sh http://127.0.0.1:3000"
+echo ""
+echo "3. View traces in Jaeger UI:"
+echo "   http://localhost:16686"
+echo ""
diff --git a/.aws-sam/build/InventoryServiceFunction/package-lock.json b/.aws-sam/build/InventoryServiceFunction/package-lock.json
new file mode 100644
index 0000000..eeb2106
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/package-lock.json
@@ -0,0 +1,295 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "lambda-opentelemetry-demo",
+      "version": "1.0.0",
+      "license": "MIT",
+      "dependencies": {
+        "axios": "^1.13.5"
+      }
+    },
+    "node_modules/asynckit": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
+      "license": "MIT"
+    },
+    "node_modules/axios": {
+      "version": "1.13.5",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.13.5.tgz",
+      "integrity": "sha512-cz4ur7Vb0xS4/KUN0tPWe44eqxrIu31me+fbang3ijiNscE129POzipJJA6zniq2C/Z6sJCjMimjS8Lc/GAs8Q==",
+      "license": "MIT",
+      "dependencies": {
+        "follow-redirects": "^1.15.11",
+        "form-data": "^4.0.5",
+        "proxy-from-env": "^1.1.0"
+      }
+    },
+    "node_modules/call-bind-apply-helpers": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
+      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/combined-stream": {
+      "version": "1.0.8",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "license": "MIT",
+      "dependencies": {
+        "delayed-stream": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
+    "node_modules/delayed-stream": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
+      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
+    "node_modules/dunder-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
+      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "gopd": "^1.2.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-define-property": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
+      "integrity": "sha512-e3nRfgfUZ4rNGL232gUgX06QNyyez04KdjFrF+LTRoOXmrOgFKDg4BCdsjW8EnT69eqdYGmRpJwiPVYNrCaW3g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-errors": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
+      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-object-atoms": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.1.tgz",
+      "integrity": "sha512-FGgH2h8zKNim9ljj7dankFPcICIK9Cp5bm+c2gQSYePhpaG5+esrLODihIorn+Pe6FGJzWhXQotPv73jTaldXA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-set-tostringtag": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/es-set-tostringtag/-/es-set-tostringtag-2.1.0.tgz",
+      "integrity": "sha512-j6vWzfrGVfyXxge+O0x5sh6cvxAog0a/4Rdd2K36zCMV5eJ+/+tOAngRO8cODMNWbVRdVlmGZQL2YS3yR8bIUA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "get-intrinsic": "^1.2.6",
+        "has-tostringtag": "^1.0.2",
+        "hasown": "^2.0.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/follow-redirects": {
+      "version": "1.15.11",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.11.tgz",
+      "integrity": "sha512-deG2P0JfjrTxl50XGCDyfI97ZGVCxIpfKYmfyrQ54n5FO/0gfIES8C/Psl6kWVDolizcaaxZJnTS0QSMxvnsBQ==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/form-data": {
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.5.tgz",
+      "integrity": "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==",
+      "license": "MIT",
+      "dependencies": {
+        "asynckit": "^0.4.0",
+        "combined-stream": "^1.0.8",
+        "es-set-tostringtag": "^2.1.0",
+        "hasown": "^2.0.2",
+        "mime-types": "^2.1.12"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/function-bind": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
+      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-intrinsic": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
+      "integrity": "sha512-9fSjSaos/fRIVIp+xSJlE6lfwhES7LNtKaCBIamHsjr2na1BiABJPo0mOjjz8GJDURarmCPGqaiVg5mfjb98CQ==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.2",
+        "es-define-property": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "es-object-atoms": "^1.1.1",
+        "function-bind": "^1.1.2",
+        "get-proto": "^1.0.1",
+        "gopd": "^1.2.0",
+        "has-symbols": "^1.1.0",
+        "hasown": "^2.0.2",
+        "math-intrinsics": "^1.1.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
+      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
+      "license": "MIT",
+      "dependencies": {
+        "dunder-proto": "^1.0.1",
+        "es-object-atoms": "^1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/gopd": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
+      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-symbols": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.1.0.tgz",
+      "integrity": "sha512-1cDNdwJ2Jaohmb3sg4OmKaMBwuC48sYni5HUw2DvsC8LjGTLK9h+eb1X6RyuOHe4hT0ULCW68iomhjUoKUqlPQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-tostringtag": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/has-tostringtag/-/has-tostringtag-1.0.2.tgz",
+      "integrity": "sha512-NqADB8VjPFLM2V0VvHUewwwsw0ZWBaIdgo+ieHtK3hasLz4qeCRjYcqfB6AQrBggRKppKF8L52/VqdVsO47Dlw==",
+      "license": "MIT",
+      "dependencies": {
+        "has-symbols": "^1.0.3"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/hasown": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.2.tgz",
+      "integrity": "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/math-intrinsics": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
+      "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/mime-db": {
+      "version": "1.52.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
+      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/mime-types": {
+      "version": "2.1.35",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
+      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/proxy-from-env": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
+      "integrity": "sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==",
+      "license": "MIT"
+    }
+  }
+}
diff --git a/.aws-sam/build/InventoryServiceFunction/package.json b/.aws-sam/build/InventoryServiceFunction/package.json
new file mode 100644
index 0000000..abe61a7
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/package.json
@@ -0,0 +1,23 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "description": "Sample AWS Lambda project demonstrating OpenTelemetry integration without CloudWatch/X-Ray",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"No tests specified\" && exit 0",
+    "deploy": "sam deploy --guided",
+    "build": "sam build"
+  },
+  "keywords": [
+    "aws",
+    "lambda",
+    "opentelemetry",
+    "tracing",
+    "nodejs"
+  ],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "axios": "^1.13.5"
+  }
+}
diff --git a/.aws-sam/build/InventoryServiceFunction/src/inventory-service/index.js b/.aws-sam/build/InventoryServiceFunction/src/inventory-service/index.js
new file mode 100644
index 0000000..7cb0b00
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/src/inventory-service/index.js
@@ -0,0 +1,143 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock inventory database
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  'item-004': { name: 'Monitor', quantity: 5 },
+  'item-005': { name: 'Headphones', quantity: 0 }, // Out of stock
+};
+
+/**
+ * Inventory Service Lambda Handler
+ * This service checks if requested items are available in inventory
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Inventory Service received event:', JSON.stringify(event));
+
+  return withSpan('check-inventory', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, items } = body;
+
+      // Validate input
+      if (!orderId || !items || !Array.isArray(items)) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing or invalid required fields',
+        });
+        return createResponse(400, {
+          available: false,
+          error: 'Missing or invalid required fields: orderId, items (array)',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'inventory.items.count': items.length,
+      });
+
+      console.log(`Checking inventory for order ${orderId}`);
+
+      // Check each item
+      const unavailableItems = [];
+      let allAvailable = true;
+
+      for (const item of items) {
+        const { itemId, quantity } = item;
+        
+        if (!itemId || !quantity) {
+          continue;
+        }
+
+        addSpanAttributes({
+          [`inventory.item.${itemId}.requested`]: quantity,
+        });
+
+        // Check if item exists in inventory
+        if (!inventory[itemId]) {
+          console.log(`Item ${itemId} not found in inventory`);
+          unavailableItems.push({
+            itemId,
+            reason: 'Item not found',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'not-found',
+          });
+          continue;
+        }
+
+        const availableQuantity = inventory[itemId].quantity;
+        addSpanAttributes({
+          [`inventory.item.${itemId}.available`]: availableQuantity,
+        });
+
+        // Check if sufficient quantity is available
+        if (availableQuantity < quantity) {
+          console.log(`Insufficient quantity for item ${itemId}. Requested: ${quantity}, Available: ${availableQuantity}`);
+          unavailableItems.push({
+            itemId,
+            name: inventory[itemId].name,
+            requestedQuantity: quantity,
+            availableQuantity: availableQuantity,
+            reason: availableQuantity === 0 ? 'Out of stock' : 'Insufficient quantity',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'insufficient',
+          });
+        } else {
+          console.log(`Item ${itemId} is available. Requested: ${quantity}, Available: ${availableQuantity}`);
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'available',
+          });
+        }
+      }
+
+      addSpanAttributes({
+        'inventory.all_available': allAvailable,
+        'inventory.unavailable_count': unavailableItems.length,
+      });
+
+      if (allAvailable) {
+        console.log(`All items available for order ${orderId}`);
+        
+        return createResponse(200, {
+          available: true,
+          orderId,
+          message: 'All items are available',
+        });
+      } else {
+        console.log(`Some items unavailable for order ${orderId}:`, unavailableItems);
+        addSpanAttributes({
+          'inventory.failure_reason': 'items-unavailable',
+        });
+        
+        return createResponse(200, {
+          available: false,
+          orderId,
+          unavailableItems,
+          message: 'Some items are not available',
+        });
+      }
+
+    } catch (error) {
+      console.error('Inventory check error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        available: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/InventoryServiceFunction/src/order-service/index.js b/.aws-sam/build/InventoryServiceFunction/src/order-service/index.js
new file mode 100644
index 0000000..7d05578
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/src/order-service/index.js
@@ -0,0 +1,181 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { callService, createResponse } = require('../shared/utils');
+
+/**
+ * Order Service Lambda Handler
+ * This service accepts orders and orchestrates calls to Inventory and Payment services
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Order Service received event:', JSON.stringify(event));
+
+  return withSpan('process-order', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, items, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !items || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, items, paymentMethod',
+        });
+      }
+
+      // Add order details to span
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'order.items.count': items.length,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing order ${orderId} for customer ${customerId}`);
+
+      // Step 1: Check inventory
+      console.log('Step 1: Checking inventory');
+      const inventoryUrl = process.env.INVENTORY_SERVICE_URL || 'http://localhost:3001/inventory';
+      
+      let inventoryResult;
+      try {
+        inventoryResult = await withSpan('check-inventory', async (inventorySpan) => {
+          addSpanAttributes({
+            'service': 'inventory',
+            'order.id': orderId,
+          });
+          
+          const result = await callService(inventoryUrl, {
+            orderId,
+            items,
+          });
+          
+          addSpanAttributes({
+            'inventory.available': result.available,
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Inventory check failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Inventory check failed',
+          details: error.message,
+        });
+      }
+
+      if (!inventoryResult.available) {
+        addSpanAttributes({
+          'inventory.status': 'out-of-stock',
+          'inventory.unavailable_items': JSON.stringify(inventoryResult.unavailableItems || []),
+        });
+        
+        console.log(`Order ${orderId} failed: Items out of stock`);
+        return createResponse(409, {
+          success: false,
+          orderId,
+          error: 'Items out of stock',
+          unavailableItems: inventoryResult.unavailableItems,
+        });
+      }
+
+      addSpanAttributes({ 'inventory.status': 'available' });
+
+      // Step 2: Process payment
+      console.log('Step 2: Processing payment');
+      const paymentUrl = process.env.PAYMENT_SERVICE_URL || 'http://localhost:3002/payment';
+      
+      let paymentResult;
+      try {
+        paymentResult = await withSpan('process-payment', async (paymentSpan) => {
+          const totalAmount = items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
+          
+          addSpanAttributes({
+            'service': 'payment',
+            'order.id': orderId,
+            'payment.method': paymentMethod,
+            'payment.amount': totalAmount,
+          });
+          
+          const result = await callService(paymentUrl, {
+            orderId,
+            customerId,
+            amount: totalAmount,
+            paymentMethod,
+          });
+          
+          addSpanAttributes({
+            'payment.success': result.success,
+            'payment.transaction_id': result.transactionId || 'none',
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Payment processing failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Payment processing failed',
+          details: error.message,
+        });
+      }
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.status': 'failed',
+          'payment.failure_reason': paymentResult.reason || 'unknown',
+        });
+        
+        console.log(`Order ${orderId} failed: Payment failed`);
+        return createResponse(402, {
+          success: false,
+          orderId,
+          error: 'Payment failed',
+          reason: paymentResult.reason,
+        });
+      }
+
+      addSpanAttributes({
+        'payment.status': 'success',
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      // Order successful
+      console.log(`Order ${orderId} completed successfully`);
+      
+      return createResponse(200, {
+        success: true,
+        orderId,
+        message: 'Order processed successfully',
+        transactionId: paymentResult.transactionId,
+        totalAmount: items.reduce((sum, item) => sum + (item.price * item.quantity), 0),
+      });
+
+    } catch (error) {
+      console.error('Order processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/InventoryServiceFunction/src/payment-service/index.js b/.aws-sam/build/InventoryServiceFunction/src/payment-service/index.js
new file mode 100644
index 0000000..6a88ea6
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/src/payment-service/index.js
@@ -0,0 +1,144 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock payment processing
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  'expired-card': ['4333333333333333', 'expired-card'],
+};
+
+/**
+ * Simulate payment processing with some failure scenarios
+ * @param {string} paymentMethod - Payment method identifier
+ * @param {number} amount - Payment amount
+ * @returns {Object} Payment result
+ */
+function processPayment(paymentMethod, amount) {
+  // Check for known failure patterns
+  for (const [reason, patterns] of Object.entries(FAILURE_PATTERNS)) {
+    if (patterns.some(pattern => paymentMethod.includes(pattern))) {
+      return {
+        success: false,
+        reason: reason.replace('-', ' '),
+        transactionId: null,
+      };
+    }
+  }
+
+  // Simulate random failures (10% chance)
+  if (Math.random() < 0.1) {
+    const reasons = ['network-timeout', 'gateway-error', 'rate-limit-exceeded'];
+    const randomReason = reasons[Math.floor(Math.random() * reasons.length)];
+    return {
+      success: false,
+      reason: randomReason.replace('-', ' '),
+      transactionId: null,
+    };
+  }
+
+  // Successful payment
+  return {
+    success: true,
+    transactionId: `txn-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`,
+  };
+}
+
+/**
+ * Payment Service Lambda Handler
+ * This service processes payments with failure scenarios for testing
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Payment Service received event:', JSON.stringify(event));
+
+  return withSpan('process-payment', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, amount, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !amount || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, amount, paymentMethod',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'payment.amount': amount,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing payment for order ${orderId}, amount: ${amount}`);
+
+      // Validate amount
+      if (amount <= 0) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Invalid payment amount',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Invalid payment amount',
+        });
+      }
+
+      // Process payment
+      const paymentResult = processPayment(paymentMethod, amount);
+
+      addSpanAttributes({
+        'payment.success': paymentResult.success,
+      });
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.failure_reason': paymentResult.reason,
+        });
+        
+        console.log(`Payment failed for order ${orderId}: ${paymentResult.reason}`);
+        
+        return createResponse(200, {
+          success: false,
+          orderId,
+          reason: paymentResult.reason,
+          message: 'Payment processing failed',
+        });
+      }
+
+      addSpanAttributes({
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      console.log(`Payment successful for order ${orderId}. Transaction ID: ${paymentResult.transactionId}`);
+
+      return createResponse(200, {
+        success: true,
+        orderId,
+        transactionId: paymentResult.transactionId,
+        amount,
+        message: 'Payment processed successfully',
+      });
+
+    } catch (error) {
+      console.error('Payment processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/InventoryServiceFunction/src/shared/tracer.js b/.aws-sam/build/InventoryServiceFunction/src/shared/tracer.js
new file mode 100644
index 0000000..3cedef5
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/src/shared/tracer.js
@@ -0,0 +1,118 @@
+// When using OpenTelemetry Lambda Layer with auto-instrumentation,
+// the @opentelemetry/api is provided by the layer at /opt/nodejs/node_modules
+const api = require('@opentelemetry/api');
+
+/**
+ * Get the current active span
+ * The Lambda Layer automatically creates spans for Lambda invocations
+ * @returns {Span} Current active span
+ */
+function getCurrentSpan() {
+  return api.trace.getActiveSpan();
+}
+
+/**
+ * Get a tracer instance
+ * @param {string} name - Tracer name (usually service name)
+ * @param {string} version - Service version
+ * @returns {Tracer} OpenTelemetry tracer instance
+ */
+function getTracer(name = 'lambda-app', version = '1.0.0') {
+  return api.trace.getTracer(name, version);
+}
+
+/**
+ * Create a new span for a specific operation
+ * @param {string} spanName - Name of the span
+ * @param {Function} fn - Function to execute within the span
+ * @param {Object} attributes - Optional span attributes
+ * @returns {Promise} Result of the function execution
+ */
+async function withSpan(spanName, fn, attributes = {}) {
+  const tracer = getTracer();
+  return tracer.startActiveSpan(spanName, async (span) => {
+    try {
+      // Add custom attributes
+      Object.entries(attributes).forEach(([key, value]) => {
+        span.setAttribute(key, value);
+      });
+      
+      const result = await fn(span);
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.setStatus({
+        code: api.SpanStatusCode.ERROR,
+        message: error.message,
+      });
+      span.recordException(error);
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+}
+
+/**
+ * Add custom attributes to the current span
+ * @param {Object} attributes - Key-value pairs of attributes to add
+ */
+function addSpanAttributes(attributes) {
+  const span = getCurrentSpan();
+  if (span) {
+    Object.entries(attributes).forEach(([key, value]) => {
+      if (value !== null && value !== undefined) {
+        span.setAttribute(key, value);
+      }
+    });
+  }
+}
+
+/**
+ * Record an exception on the current span
+ * @param {Error} error - Error to record
+ */
+function recordException(error) {
+  const span = getCurrentSpan();
+  if (span) {
+    span.recordException(error);
+    span.setStatus({
+      code: api.SpanStatusCode.ERROR,
+      message: error.message,
+    });
+  }
+}
+
+/**
+ * Inject trace context into headers for downstream service calls
+ * Uses W3C Trace Context propagation
+ * @returns {Object} Headers with trace context
+ */
+function injectTraceContext() {
+  const headers = {};
+  const span = getCurrentSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    if (spanContext && spanContext.traceId && spanContext.spanId) {
+      // W3C Trace Context format
+      const traceFlags = spanContext.traceFlags || 0;
+      headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-${traceFlags.toString(16).padStart(2, '0')}`;
+      
+      if (spanContext.traceState) {
+        headers.tracestate = spanContext.traceState.serialize();
+      }
+    }
+  }
+  
+  return headers;
+}
+
+module.exports = {
+  getTracer,
+  getCurrentSpan,
+  withSpan,
+  addSpanAttributes,
+  recordException,
+  injectTraceContext,
+};
diff --git a/.aws-sam/build/InventoryServiceFunction/src/shared/utils.js b/.aws-sam/build/InventoryServiceFunction/src/shared/utils.js
new file mode 100644
index 0000000..2da73e3
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/src/shared/utils.js
@@ -0,0 +1,61 @@
+const axios = require('axios');
+const { injectTraceContext } = require('./tracer');
+
+/**
+ * Make an HTTP request to another Lambda service with trace context propagation
+ * @param {string} url - Service URL
+ * @param {Object} data - Request payload
+ * @param {string} method - HTTP method (default: POST)
+ * @returns {Promise<Object>} Response data
+ */
+async function callService(url, data, method = 'POST') {
+  // Inject trace context into headers
+  const headers = {
+    'Content-Type': 'application/json',
+    ...injectTraceContext(),
+  };
+
+  console.log(`Calling service: ${url} with method: ${method}`);
+  console.log(`Trace context headers:`, headers);
+
+  try {
+    const response = await axios({
+      method,
+      url,
+      data,
+      headers,
+    });
+
+    console.log(`Service call successful: ${url}`);
+    return response.data;
+  } catch (error) {
+    console.error(`Service call failed: ${url}`, error.message);
+    if (error.response) {
+      throw new Error(`Service call failed: ${error.response.status} - ${JSON.stringify(error.response.data)}`);
+    }
+    throw error;
+  }
+}
+
+/**
+ * Create a Lambda response object
+ * @param {number} statusCode - HTTP status code
+ * @param {Object} body - Response body
+ * @param {Object} headers - Additional headers
+ * @returns {Object} Lambda response object
+ */
+function createResponse(statusCode, body, headers = {}) {
+  return {
+    statusCode,
+    headers: {
+      'Content-Type': 'application/json',
+      ...headers,
+    },
+    body: JSON.stringify(body),
+  };
+}
+
+module.exports = {
+  callService,
+  createResponse,
+};
diff --git a/.aws-sam/build/InventoryServiceFunction/template.yaml b/.aws-sam/build/InventoryServiceFunction/template.yaml
new file mode 100644
index 0000000..bc11944
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/template.yaml
@@ -0,0 +1,137 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: Lambda OpenTelemetry Demo - Order, Inventory, and Payment Services with AWS ADOT Layer
+
+Globals:
+  Function:
+    Timeout: 30
+    MemorySize: 512
+    Runtime: nodejs20.x
+    Environment:
+      Variables:
+        AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+        OTEL_SERVICE_NAME: will-be-overridden
+        OTEL_TRACES_SAMPLER: AlwaysOn
+        OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+        OTEL_EXPORTER_OTLP_ENDPOINT: !Ref OtelCollectorEndpoint
+        OTEL_PROPAGATORS: tracecontext
+        OTEL_RESOURCE_ATTRIBUTES: !Sub deployment.environment=${Environment}
+
+Parameters:
+  OtelCollectorEndpoint:
+    Type: String
+    Default: 'http://localhost:4318'
+    Description: OpenTelemetry Collector endpoint URL (without /v1/traces path)
+  
+  Environment:
+    Type: String
+    Default: 'production'
+    Description: Deployment environment (e.g., development, staging, production)
+  
+  AdotLayerArn:
+    Type: String
+    Default: 'arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5'
+    Description: |
+      ARN of the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for Node.js.
+      Find the latest ARN for your region at:
+      https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Resources:
+  # Order Service Function
+  OrderServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: order-service
+      CodeUri: ./
+      Handler: src/order-service/index.handler
+      Description: Order Service - Orchestrates order processing
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: order-service
+          INVENTORY_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+          PAYMENT_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+      Events:
+        OrderApi:
+          Type: Api
+          Properties:
+            Path: /order
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Inventory Service Function
+  InventoryServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: inventory-service
+      CodeUri: ./
+      Handler: src/inventory-service/index.handler
+      Description: Inventory Service - Checks item availability
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: inventory-service
+      Events:
+        InventoryApi:
+          Type: Api
+          Properties:
+            Path: /inventory
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Payment Service Function
+  PaymentServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: payment-service
+      CodeUri: ./
+      Handler: src/payment-service/index.handler
+      Description: Payment Service - Processes payments
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: payment-service
+      Events:
+        PaymentApi:
+          Type: Api
+          Properties:
+            Path: /payment
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # API Gateway
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+      Description: API Gateway for Lambda OpenTelemetry Demo
+
+Outputs:
+  ApiEndpoint:
+    Description: API Gateway endpoint URL
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod'
+  
+  OrderServiceUrl:
+    Description: Order Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/order'
+    
+  InventoryServiceUrl:
+    Description: Inventory Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+    
+  PaymentServiceUrl:
+    Description: Payment Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+  
+  AdotLayerVersion:
+    Description: ADOT Lambda Layer ARN being used
+    Value: !Ref AdotLayerArn
diff --git a/.aws-sam/build/InventoryServiceFunction/test-api.sh b/.aws-sam/build/InventoryServiceFunction/test-api.sh
new file mode 100755
index 0000000..680b864
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/test-api.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+
+# Color codes for output
+GREEN='\033[0;32m'
+BLUE='\033[0;34m'
+YELLOW='\033[1;33m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+echo -e "${BLUE}========================================${NC}"
+echo -e "${BLUE}Lambda OpenTelemetry Demo - Test Script${NC}"
+echo -e "${BLUE}========================================${NC}"
+echo ""
+
+# Check if API endpoint is provided
+if [ -z "$1" ]; then
+    echo -e "${RED}Error: API endpoint is required${NC}"
+    echo "Usage: ./test-api.sh <API_ENDPOINT>"
+    echo "Example: ./test-api.sh https://abc123.execute-api.us-east-1.amazonaws.com/Prod"
+    exit 1
+fi
+
+API_ENDPOINT=$1
+ORDER_URL="${API_ENDPOINT}/order"
+
+echo -e "${YELLOW}Using API Endpoint: ${API_ENDPOINT}${NC}"
+echo ""
+
+# Test 1: Successful Order
+echo -e "${BLUE}Test 1: Successful Order${NC}"
+echo "Testing with items that are in stock and valid payment method..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 2: Out of Stock Order
+echo -e "${BLUE}Test 2: Out of Stock Order${NC}"
+echo "Testing with items that are out of stock..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 3: Payment Failure (Card Declined)
+echo -e "${BLUE}Test 3: Payment Failure - Card Declined${NC}"
+echo "Testing with a payment method that will be declined..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 4: Payment Failure (Insufficient Funds)
+echo -e "${BLUE}Test 4: Payment Failure - Insufficient Funds${NC}"
+echo "Testing with insufficient funds scenario..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+echo -e "${GREEN}========================================${NC}"
+echo -e "${GREEN}All tests completed!${NC}"
+echo -e "${GREEN}Check your OpenTelemetry backend to view the traces${NC}"
+echo -e "${GREEN}========================================${NC}"
diff --git a/.aws-sam/build/InventoryServiceFunction/test-payloads.json b/.aws-sam/build/InventoryServiceFunction/test-payloads.json
new file mode 100644
index 0000000..603d30c
--- /dev/null
+++ b/.aws-sam/build/InventoryServiceFunction/test-payloads.json
@@ -0,0 +1,66 @@
+{
+  "successfulOrder": {
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  },
+  "outOfStockOrder": {
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  },
+  "paymentFailureOrder": {
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  },
+  "insufficientFundsOrder": {
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }
+}
diff --git a/.aws-sam/build/OrderServiceFunction/.env.example b/.aws-sam/build/OrderServiceFunction/.env.example
new file mode 100644
index 0000000..3f3aa74
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/.env.example
@@ -0,0 +1,7 @@
+# OpenTelemetry Configuration
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318/v1/traces
+ENVIRONMENT=development
+
+# Service URLs (for local testing)
+INVENTORY_SERVICE_URL=http://localhost:3001/inventory
+PAYMENT_SERVICE_URL=http://localhost:3002/payment
diff --git a/.aws-sam/build/OrderServiceFunction/ADOT-LAYER-CONFIG.md b/.aws-sam/build/OrderServiceFunction/ADOT-LAYER-CONFIG.md
new file mode 100644
index 0000000..cffddc9
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/ADOT-LAYER-CONFIG.md
@@ -0,0 +1,366 @@
+# AWS ADOT Lambda Layer Configuration Guide
+
+This document explains how to configure and use the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for automatic instrumentation.
+
+## Overview
+
+The AWS ADOT Lambda Layer provides automatic OpenTelemetry instrumentation for Lambda functions without requiring you to bundle OpenTelemetry SDKs in your deployment package.
+
+## Layer ARNs by Region
+
+### Node.js 18.x ADOT Layer ARNs (Latest: v1-18-1)
+
+| Region | ARN |
+|--------|-----|
+| us-east-1 | `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-east-2 | `arn:aws:lambda:us-east-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-1 | `arn:aws:lambda:us-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-2 | `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-west-1 | `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-central-1 | `arn:aws:lambda:eu-central-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-southeast-1 | `arn:aws:lambda:ap-southeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-northeast-1 | `arn:aws:lambda:ap-northeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+
+**Find the latest ARNs**: https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+## Required Environment Variables
+
+### Essential Configuration
+
+```yaml
+Environment:
+  Variables:
+    # Enable ADOT auto-instrumentation wrapper
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+    
+    # Service name for identification in traces
+    OTEL_SERVICE_NAME: your-service-name
+    
+    # Sampling configuration (AlwaysOn for demo, adjust for production)
+    OTEL_TRACES_SAMPLER: AlwaysOn
+    
+    # Protocol for OTLP export
+    OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+    
+    # OpenTelemetry Collector endpoint (without /v1/traces)
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://your-collector:4318
+    
+    # Trace context propagation format
+    OTEL_PROPAGATORS: tracecontext
+```
+
+### Advanced Configuration Options
+
+```yaml
+Environment:
+  Variables:
+    # Resource attributes (for environment, version, etc.)
+    OTEL_RESOURCE_ATTRIBUTES: deployment.environment=production,service.version=1.0.0
+    
+    # Specific endpoint for traces (optional, overrides OTEL_EXPORTER_OTLP_ENDPOINT)
+    OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: http://your-collector:4318/v1/traces
+    
+    # Enable/disable specific instrumentations
+    OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: true
+    OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+    
+    # Span attribute limits
+    OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT: 4095
+    OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 128
+```
+
+## Exporter Backends
+
+### 1. Jaeger (Local Development)
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://localhost:4318
+OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+```
+
+Run Jaeger with OTLP support:
+```bash
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+```
+
+### 2. AWS X-Ray (with ADOT Collector)
+
+If you want to send traces to AWS X-Ray, deploy an ADOT Collector in your VPC:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://adot-collector:4318
+OTEL_PROPAGATORS: tracecontext,xray
+```
+
+ADOT Collector configuration:
+```yaml
+receivers:
+  otlp:
+    protocols:
+      http:
+        endpoint: 0.0.0.0:4318
+
+exporters:
+  awsxray:
+    region: us-east-1
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      exporters: [awsxray]
+```
+
+### 3. Grafana Cloud / Honeycomb / DataDog
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: https://your-saas-endpoint
+OTEL_EXPORTER_OTLP_HEADERS: Authorization=Bearer your-api-key
+```
+
+### 4. Self-Hosted OpenTelemetry Collector
+
+Deploy a collector in your VPC or use Lambda Extension:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+## How Auto-Instrumentation Works
+
+### 1. Wrapper Execution
+
+The `AWS_LAMBDA_EXEC_WRAPPER` environment variable points to `/opt/otel-handler`, which:
+- Initializes the OpenTelemetry SDK before your handler
+- Automatically instruments common libraries (http, https, aws-sdk, etc.)
+- Creates a root span for each Lambda invocation
+- Propagates trace context from incoming requests
+
+### 2. Automatic Instrumentation
+
+The layer automatically instruments:
+- ✅ AWS SDK calls
+- ✅ HTTP/HTTPS requests (axios, node-fetch, http, https)
+- ✅ Lambda invocation (creates root span)
+- ✅ Downstream service calls with trace context propagation
+
+### 3. Context Propagation
+
+The layer automatically:
+- Extracts W3C trace context from incoming API Gateway requests
+- Injects trace context into outgoing HTTP requests
+- Maintains trace context across async operations
+
+## Usage in Your Code
+
+### Basic Usage (Automatic)
+
+With the layer configured, your Lambda function is automatically instrumented:
+
+```javascript
+exports.handler = async (event) => {
+  // Automatically traced!
+  const response = await axios.get('https://api.example.com');
+  return { statusCode: 200, body: JSON.stringify(response.data) };
+};
+```
+
+### Adding Custom Spans
+
+For additional business logic spans:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service', '1.0.0');
+  
+  return tracer.startActiveSpan('business-operation', async (span) => {
+    try {
+      span.setAttribute('customer.id', event.customerId);
+      
+      // Your business logic
+      const result = await processOrder(event);
+      
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.recordException(error);
+      span.setStatus({ code: api.SpanStatusCode.ERROR });
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+};
+```
+
+### Adding Attributes to Current Span
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const span = api.trace.getActiveSpan();
+  if (span) {
+    span.setAttribute('order.id', event.orderId);
+    span.setAttribute('order.amount', event.amount);
+  }
+  
+  // Your handler logic
+};
+```
+
+## Trace Context Propagation
+
+### Automatic (HTTP Clients)
+
+The layer automatically propagates context for instrumented HTTP clients:
+
+```javascript
+const axios = require('axios');
+
+// Trace context is automatically added to headers!
+const response = await axios.post('https://api.example.com/payment', data);
+```
+
+### Manual (Custom Clients)
+
+For custom HTTP clients or non-instrumented libraries:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+function getTraceHeaders() {
+  const headers = {};
+  const span = api.trace.getActiveSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-01`;
+  }
+  
+  return headers;
+}
+
+// Use in your custom client
+const headers = { ...getTraceHeaders(), 'Content-Type': 'application/json' };
+```
+
+## Sampling
+
+### AlwaysOn (Development/Demo)
+
+```yaml
+OTEL_TRACES_SAMPLER: AlwaysOn
+```
+
+Traces every request. Good for development but expensive in production.
+
+### TraceIdRatioBased (Production)
+
+```yaml
+OTEL_TRACES_SAMPLER: TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1  # 10% sampling
+```
+
+Samples a percentage of requests to reduce costs.
+
+### ParentBased (Recommended)
+
+```yaml
+OTEL_TRACES_SAMPLER: ParentBased_TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1
+```
+
+Respects parent sampling decisions while applying ratio-based sampling to root spans.
+
+## Performance Considerations
+
+### Cold Start Impact
+
+The ADOT layer adds ~200-300ms to cold start time:
+- Layer initialization: ~100ms
+- Auto-instrumentation setup: ~100-200ms
+
+### Runtime Overhead
+
+- Minimal overhead during warm execution (<5ms per invocation)
+- Async span export doesn't block Lambda execution
+- Batching reduces network calls
+
+### Optimization Tips
+
+1. **Use provisioned concurrency** for latency-sensitive functions
+2. **Adjust span limits** to reduce memory usage:
+   ```yaml
+   OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 32
+   OTEL_SPAN_EVENT_COUNT_LIMIT: 32
+   ```
+3. **Use sampling** in high-volume environments
+4. **Disable unused instrumentations**:
+   ```yaml
+   OTEL_INSTRUMENTATION_AWS_LAMBDA_ENABLED: true
+   OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+   OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: false
+   ```
+
+## Troubleshooting
+
+### No Traces Appearing
+
+1. Check CloudWatch Logs for ADOT errors:
+   ```
+   grep "otel" /aws/lambda/your-function
+   ```
+
+2. Verify environment variables:
+   ```bash
+   aws lambda get-function-configuration --function-name your-function \
+     --query 'Environment.Variables'
+   ```
+
+3. Test collector endpoint connectivity:
+   - Ensure Lambda has network access to the collector
+   - Check security groups and NACLs
+   - Verify collector is accepting OTLP HTTP on port 4318
+
+### Wrapper Not Running
+
+Error: `AWS_LAMBDA_EXEC_WRAPPER is set but the wrapper does not exist`
+
+**Solution**: Verify the layer ARN is correct and matches your region.
+
+### Trace Context Not Propagating
+
+1. Ensure `OTEL_PROPAGATORS=tracecontext` is set
+2. Check if HTTP library is supported (axios, node-fetch, http, https)
+3. For unsupported libraries, manually inject headers
+
+### High Cold Start Times
+
+1. Consider using Lambda SnapStart (if available)
+2. Use provisioned concurrency
+3. Minimize layer count (combine layers if possible)
+4. Profile and optimize your application code
+
+## Best Practices
+
+1. **Set meaningful service names**: Use descriptive names that reflect the business function
+2. **Add business context**: Include order IDs, customer IDs, and other relevant attributes
+3. **Handle errors properly**: Record exceptions and set error status on spans
+4. **Use semantic conventions**: Follow OpenTelemetry semantic conventions for consistency
+5. **Monitor collector health**: Ensure your collector is performant and highly available
+6. **Set appropriate sampling**: Balance cost with observability needs
+7. **Use tags for filtering**: Add environment, version, and region as resource attributes
+
+## References
+
+- AWS ADOT Lambda: https://aws-otel.github.io/docs/getting-started/lambda
+- OpenTelemetry Lambda Instrumentation: https://opentelemetry.io/docs/platforms/faas/lambda-auto-instrument/
+- W3C Trace Context: https://www.w3.org/TR/trace-context/
+- OpenTelemetry Semantic Conventions: https://opentelemetry.io/docs/specs/semconv/
diff --git a/.aws-sam/build/OrderServiceFunction/ARCHITECTURE.md b/.aws-sam/build/OrderServiceFunction/ARCHITECTURE.md
new file mode 100644
index 0000000..ff7e7c2
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/ARCHITECTURE.md
@@ -0,0 +1,366 @@
+# Architecture Details
+
+## Service Flow
+
+### 1. Successful Order Flow
+
+```
+Client
+  │
+  │ POST /order
+  ├─────────────────────────────────────────┐
+  │                                         │
+  ▼                                         │
+Order Service                               │
+  │                                         │
+  │ 1. Validate request                     │
+  │ 2. Create root span                     │
+  │                                         │
+  │ POST /inventory (with trace context)    │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Inventory Service               │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Check stock levels       │           │
+  │ 4. Return availability      │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: available=true    │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ POST /payment (with trace context)      │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Payment Service                 │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Process payment          │           │
+  │ 4. Return result            │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: success=true      │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ Complete order processing   │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: 200 OK            │           │
+  ▼                             │           │
+Client ◄──────────────────────────────────────┘
+```
+
+### 2. Out of Stock Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Out of stock detected)
+                       ← 
+         Order Service 
+         (Skip payment, return 409)
+       ←
+Client
+```
+
+### 3. Payment Failure Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Items available)
+                       ← 
+         Order Service → Payment Service
+                         (Payment failed)
+                       ←
+         Order Service
+         (Return 402)
+       ←
+Client
+```
+
+## Trace Structure
+
+### Trace Hierarchy
+
+```
+Trace ID: 00000000000000000000000000000001
+│
+└─ Span: process-order (Order Service)
+   │ Duration: 245ms
+   │ Attributes:
+   │   - order.id: ORD-001
+   │   - customer.id: CUST-123
+   │   - order.items.count: 2
+   │
+   ├─ Span: check-inventory (Order Service)
+   │  │ Duration: 15ms
+   │  │ Attributes:
+   │  │   - service: inventory
+   │  │   - order.id: ORD-001
+   │  │
+   │  └─ Span: HTTP POST (Auto-instrumented)
+   │     │ Duration: 12ms
+   │     │
+   │     └─ Span: check-inventory (Inventory Service)
+   │        Duration: 8ms
+   │        Attributes:
+   │          - inventory.available: true
+   │          - inventory.items.count: 2
+   │
+   └─ Span: process-payment (Order Service)
+      │ Duration: 180ms
+      │ Attributes:
+      │   - service: payment
+      │   - order.id: ORD-001
+      │   - payment.method: credit-card-5555
+      │   - payment.amount: 1059.97
+      │
+      └─ Span: HTTP POST (Auto-instrumented)
+         │ Duration: 175ms
+         │
+         └─ Span: process-payment (Payment Service)
+            Duration: 170ms
+            Attributes:
+              - payment.success: true
+              - payment.transaction_id: txn-1234567890-abc123
+```
+
+## OpenTelemetry Components
+
+### 1. Tracer Provider
+
+Manages the lifecycle of tracers and span processors.
+
+```javascript
+const provider = new NodeTracerProvider({
+  resource: resource,
+});
+```
+
+### 2. OTLP Exporter
+
+Exports spans to OpenTelemetry Collector using HTTP.
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: 'http://localhost:4318/v1/traces',
+});
+```
+
+### 3. Batch Span Processor
+
+Batches spans before export for efficiency.
+
+```javascript
+provider.addSpanProcessor(new BatchSpanProcessor(exporter));
+```
+
+### 4. Auto Instrumentations
+
+Automatically instruments common libraries.
+
+```javascript
+registerInstrumentations({
+  instrumentations: [
+    getNodeAutoInstrumentations({
+      '@opentelemetry/instrumentation-http': { enabled: true },
+      '@opentelemetry/instrumentation-https': { enabled: true },
+    }),
+  ],
+});
+```
+
+## Trace Context Propagation
+
+### W3C Trace Context Format
+
+```
+traceparent: 00-<trace-id>-<span-id>-<trace-flags>
+
+Example:
+traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+            │  │                                │                │
+            │  └─ Trace ID (32 hex chars)      │                └─ Flags
+            │                                   └─ Parent Span ID (16 hex chars)
+            └─ Version (00)
+```
+
+### Context Injection
+
+When Order Service calls Inventory Service:
+
+```javascript
+// Order Service
+const headers = injectTraceContext();
+// headers = { traceparent: '00-...-...-01' }
+
+axios.post(inventoryUrl, data, { headers });
+```
+
+### Context Extraction
+
+When Inventory Service receives request:
+
+```javascript
+// Inventory Service
+const traceContext = extractTraceContext(event);
+// Continue the trace with the same trace ID
+```
+
+## Span Attributes
+
+### Semantic Conventions
+
+Following OpenTelemetry semantic conventions:
+
+| Attribute | Description | Example |
+|-----------|-------------|---------|
+| `service.name` | Service identifier | `order-service` |
+| `service.version` | Service version | `1.0.0` |
+| `deployment.environment` | Environment | `production` |
+| `order.id` | Order identifier | `ORD-001` |
+| `customer.id` | Customer identifier | `CUST-123` |
+| `payment.amount` | Payment amount | `1059.97` |
+| `payment.method` | Payment method | `credit-card-5555` |
+| `inventory.available` | Availability flag | `true` |
+| `http.method` | HTTP method | `POST` |
+| `http.status_code` | HTTP status | `200` |
+
+## Error Handling
+
+### Error Span Status
+
+```javascript
+span.setStatus({
+  code: api.SpanStatusCode.ERROR,
+  message: error.message,
+});
+span.recordException(error);
+```
+
+### Business Logic Errors vs Technical Errors
+
+- **Business Logic Errors** (out of stock, payment declined):
+  - Span status: OK
+  - Custom attributes indicate business failure
+  - Example: `inventory.available: false`
+
+- **Technical Errors** (network failure, invalid input):
+  - Span status: ERROR
+  - Exception recorded
+  - Stack trace captured
+
+## Performance Considerations
+
+### Batch Processing
+
+Spans are batched before export to reduce network overhead:
+
+```javascript
+new BatchSpanProcessor(exporter, {
+  maxQueueSize: 2048,
+  maxExportBatchSize: 512,
+  scheduledDelayMillis: 5000,
+})
+```
+
+### Sampling
+
+For high-volume systems, implement sampling:
+
+```javascript
+const sampler = new TraceIdRatioBasedSampler(0.1); // 10% sampling
+const provider = new NodeTracerProvider({
+  resource: resource,
+  sampler: sampler,
+});
+```
+
+### Async Export
+
+Span export is asynchronous and doesn't block Lambda execution.
+
+## Security
+
+### Securing OTLP Endpoint
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
+  headers: {
+    'Authorization': `Bearer ${process.env.OTEL_API_KEY}`,
+  },
+});
+```
+
+### Data Privacy
+
+- Avoid capturing sensitive data in spans
+- Redact PII from span attributes
+- Use attribute filtering in the collector
+
+## Monitoring and Alerting
+
+### Key Metrics to Monitor
+
+1. **Trace Completeness**
+   - Percentage of complete traces
+   - Missing spans
+
+2. **Error Rates**
+   - Spans with ERROR status
+   - Service-specific error rates
+
+3. **Latency**
+   - P50, P95, P99 latencies
+   - Per-service latency breakdown
+
+4. **Business Metrics**
+   - Order success rate
+   - Payment failure rate
+   - Inventory unavailability rate
+
+### Example Queries (Jaeger)
+
+```
+# Find all failed orders
+service="order-service" AND error=true
+
+# Find orders with payment failures
+service="payment-service" AND payment.success=false
+
+# Find slow orders (> 1s)
+service="order-service" AND duration>1000ms
+
+# Find out-of-stock scenarios
+service="inventory-service" AND inventory.available=false
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Traces not appearing**
+   - Check OTLP endpoint connectivity
+   - Verify Lambda has network access
+   - Check CloudWatch logs for export errors
+
+2. **Broken traces**
+   - Verify trace context propagation
+   - Check HTTP header forwarding
+   - Ensure consistent trace ID format
+
+3. **High latency**
+   - Review span processor configuration
+   - Check collector performance
+   - Consider async export optimization
+
+4. **Missing spans**
+   - Verify auto-instrumentation is active
+   - Check for exceptions during span creation
+   - Review sampling configuration
diff --git a/.aws-sam/build/OrderServiceFunction/README.md b/.aws-sam/build/OrderServiceFunction/README.md
new file mode 100644
index 0000000..aff152d
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/README.md
@@ -0,0 +1,476 @@
+# Lambda OpenTelemetry Demo
+
+A comprehensive AWS Lambda project demonstrating how to integrate OpenTelemetry for end-to-end distributed tracing across multiple microservices **without using AWS CloudWatch or X-Ray**, using the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation.
+
+## 🎯 Overview
+
+This project implements a realistic e-commerce order processing workflow using three Lambda functions representing distinct microservices:
+
+1. **Order Service** - Orchestrates the order processing workflow
+2. **Inventory Service** - Validates item availability
+3. **Payment Service** - Processes payments
+
+The services communicate with each other while propagating trace context using OpenTelemetry, enabling complete visibility into request flows across all services.
+
+## 🏗️ Architecture
+
+```
+┌─────────────────┐
+│  Order Service  │
+│   (Lambda)      │
+└────────┬────────┘
+         │
+         ├──────────────────┐
+         │                  │
+         ▼                  ▼
+┌─────────────────┐  ┌─────────────────┐
+│ Inventory Svc   │  │  Payment Svc    │
+│   (Lambda)      │  │   (Lambda)      │
+└─────────────────┘  └─────────────────┘
+         │                  │
+         └──────┬───────────┘
+                ▼
+        OpenTelemetry
+         Collector
+                │
+                ▼
+        Tracing Backend
+      (Jaeger/Zipkin/etc)
+```
+
+## ✨ Features
+
+- ✅ **AWS ADOT Lambda Layer** - Uses AWS Distro for OpenTelemetry Lambda Layer for zero-code instrumentation
+- ✅ **Automatic Instrumentation** - Auto-instruments Lambda, HTTP/HTTPS, and AWS SDK without code changes
+- ✅ **Distributed Tracing** - End-to-end trace propagation across Lambda functions
+- ✅ **W3C Trace Context** - Standard trace context propagation using W3C format
+- ✅ **OTLP Export** - Exports traces using OTLP HTTP protocol
+- ✅ **Custom Spans** - Manual span creation for business logic insights
+- ✅ **No CloudWatch/X-Ray** - Direct export to any OpenTelemetry-compatible backend
+- ✅ **Error Scenarios** - Built-in test scenarios for:
+  - Out of stock items
+  - Payment failures (card declined, insufficient funds)
+  - Network errors
+
+## 📋 Prerequisites
+
+- Node.js 18.x or later
+- AWS CLI configured with appropriate credentials
+- AWS SAM CLI for deployment
+- OpenTelemetry Collector or compatible backend (Jaeger, Zipkin, etc.)
+
+## 🚀 Quick Start
+
+### 1. Install Dependencies
+
+```bash
+npm install
+```
+
+### 2. Set Up OpenTelemetry Backend
+
+You need an OpenTelemetry-compatible backend to receive and visualize traces. Here are some options:
+
+#### Option A: Jaeger (Recommended for local testing)
+
+```bash
+# Run Jaeger all-in-one with Docker (or use docker-compose)
+docker-compose up -d jaeger
+
+# Or manually:
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+
+# Access Jaeger UI at http://localhost:16686
+```
+
+#### Option B: Zipkin
+
+```bash
+# Run Zipkin with Docker
+docker run -d --name zipkin \
+  -p 9411:9411 \
+  openzipkin/zipkin:latest
+
+# Note: You'll need an OpenTelemetry Collector to convert OTLP to Zipkin format
+```
+
+#### Option C: Grafana Cloud, Honeycomb, or other SaaS providers
+
+Configure the OTEL_EXPORTER_OTLP_ENDPOINT parameter with your provider's endpoint.
+
+### 3. Update Lambda Layer ARN
+
+**Important**: Update the `AdotLayerArn` parameter in `template.yaml` with the correct ARN for your AWS region.
+
+Find the latest ARN for your region here:
+- https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Example ARNs:
+- **us-east-1**: `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **us-west-2**: `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **eu-west-1**: `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+
+See [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md) for complete list.
+
+### 4. Deploy to AWS
+
+```bash
+# Build the Lambda functions
+sam build
+
+# Deploy (follow the prompts)
+sam deploy --guided
+
+# Note the API endpoint from the outputs
+```
+
+During `sam deploy --guided`, you'll be prompted to provide:
+- **Stack name** (e.g., `lambda-otel-demo`)
+- **AWS Region** (e.g., `us-east-1`)
+- **OtelCollectorEndpoint** - Your OpenTelemetry Collector endpoint without `/v1/traces` (e.g., `http://your-collector:4318`)
+- **Environment** - Deployment environment (e.g., `production`, `staging`)
+- **AdotLayerArn** - AWS ADOT Lambda Layer ARN for your region
+- Confirm changes before deployment
+
+**Note**: If you're using a collector in a VPC, ensure your Lambda functions have VPC access configured.
+
+### 5. Test the Services
+
+Use the provided test script:
+
+```bash
+# Replace with your actual API endpoint from SAM deploy output
+./test-api.sh https://your-api-id.execute-api.region.amazonaws.com/Prod
+```
+
+Or manually test with curl:
+
+```bash
+# Successful order
+curl -X POST https://your-api-endpoint/Prod/order \
+  -H "Content-Type: application/json" \
+  -d @test-payloads.json
+```
+
+### 6. View Traces
+
+Open your tracing backend UI:
+- Jaeger: http://localhost:16686
+- Select service: `order-service`
+- Click "Find Traces" to view the end-to-end traces
+
+## 🔧 AWS ADOT Lambda Layer
+
+This project uses the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation. The layer provides:
+
+### Key Benefits
+
+1. **Zero-Code Instrumentation** - Auto-instruments your Lambda function without code changes
+2. **No Dependency Bundling** - OpenTelemetry SDKs are provided by the layer, reducing deployment package size
+3. **Automatic Context Propagation** - Trace context is automatically propagated across service calls
+4. **AWS-Optimized** - Maintained and supported by AWS with regular updates
+
+### How It Works
+
+The layer works through the `AWS_LAMBDA_EXEC_WRAPPER` environment variable:
+
+```yaml
+Environment:
+  Variables:
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler  # Enables auto-instrumentation
+    OTEL_SERVICE_NAME: order-service              # Service identifier
+    OTEL_TRACES_SAMPLER: AlwaysOn                 # Sampling strategy
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+When your Lambda function is invoked:
+1. The wrapper initializes OpenTelemetry SDK
+2. Auto-instrumentation is activated for HTTP, AWS SDK, and Lambda runtime
+3. A root span is created for the Lambda invocation
+4. Your handler executes within the trace context
+5. Spans are exported to your configured OTLP endpoint
+
+### What Gets Instrumented Automatically
+
+- ✅ Lambda function invocations
+- ✅ HTTP/HTTPS requests (axios, node-fetch, native http/https)
+- ✅ AWS SDK v2 and v3 calls
+- ✅ Database clients (when using instrumented libraries)
+- ✅ Trace context propagation in headers
+
+### Adding Custom Instrumentation
+
+While the layer handles most instrumentation automatically, you can add custom spans for business logic:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service');
+  
+  return tracer.startActiveSpan('custom-operation', async (span) => {
+    span.setAttribute('business.attribute', 'value');
+    // Your logic here
+    span.end();
+  });
+};
+```
+
+For detailed configuration options, see [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md).
+
+## 📝 Test Scenarios
+
+### Scenario 1: Successful Order ✅
+
+Tests the happy path where all services succeed.
+
+```json
+{
+  "orderId": "ORD-001",
+  "customerId": "CUST-123",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-001",
+      "name": "Laptop",
+      "quantity": 1,
+      "price": 999.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Success)
+- Order completed with HTTP 200
+
+### Scenario 2: Out of Stock ⚠️
+
+Tests inventory unavailability.
+
+```json
+{
+  "orderId": "ORD-002",
+  "customerId": "CUST-456",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-003",
+      "name": "Keyboard",
+      "quantity": 1,
+      "price": 79.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Out of stock detected)
+- Payment Service NOT called
+- Order fails with HTTP 409
+
+**Out of Stock Items:**
+- `item-003` - Keyboard (0 in stock)
+- `item-005` - Headphones (0 in stock)
+
+### Scenario 3: Payment Failure 💳
+
+Tests payment processing failures.
+
+**Card Declined:**
+```json
+{
+  "orderId": "ORD-003",
+  "customerId": "CUST-789",
+  "paymentMethod": "4111111111111111",
+  "items": [{"itemId": "item-001", "quantity": 1, "price": 999.99}]
+}
+```
+
+**Insufficient Funds:**
+```json
+{
+  "orderId": "ORD-004",
+  "customerId": "CUST-999",
+  "paymentMethod": "4222222222222222",
+  "items": [{"itemId": "item-004", "quantity": 2, "price": 399.99}]
+}
+```
+
+**Test Payment Methods:**
+- `4111111111111111` - Card declined
+- `4222222222222222` - Insufficient funds
+- `4333333333333333` - Expired card
+- Any other value - Success (with 10% random failure rate)
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Payment fails)
+- Order fails with HTTP 402
+
+## 🔍 Understanding the Traces
+
+Each trace will show:
+
+1. **Span Attributes:**
+   - Order ID, Customer ID
+   - Item counts and details
+   - Payment amounts and methods
+   - Service names and versions
+   - Success/failure reasons
+
+2. **Span Hierarchy:**
+   ```
+   process-order (Order Service)
+   ├── check-inventory (Order Service -> Inventory Service)
+   │   └── check-inventory (Inventory Service)
+   └── process-payment (Order Service -> Payment Service)
+       └── process-payment (Payment Service)
+   ```
+
+3. **Trace Context Propagation:**
+   - Trace IDs are consistent across all services
+   - Parent-child relationships are maintained
+   - W3C traceparent headers are used
+
+## 🛠️ Configuration
+
+### Environment Variables
+
+Configure these in the SAM template or Lambda console:
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT` - OpenTelemetry Collector endpoint (default: `http://localhost:4318/v1/traces`)
+- `ENVIRONMENT` - Deployment environment (default: `development`)
+- `INVENTORY_SERVICE_URL` - Inventory service endpoint
+- `PAYMENT_SERVICE_URL` - Payment service endpoint
+
+### Inventory Configuration
+
+Modify the mock inventory in `src/inventory-service/index.js`:
+
+```javascript
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  // Add more items...
+};
+```
+
+### Payment Configuration
+
+Modify failure patterns in `src/payment-service/index.js`:
+
+```javascript
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  // Add more patterns...
+};
+```
+
+## 📂 Project Structure
+
+```
+lambda-opentelemetry-demo/
+├── src/
+│   ├── order-service/          # Order orchestration service
+│   │   └── index.js
+│   ├── inventory-service/      # Inventory check service
+│   │   └── index.js
+│   ├── payment-service/        # Payment processing service
+│   │   └── index.js
+│   └── shared/                 # Shared utilities
+│       ├── tracer.js           # OpenTelemetry setup
+│       └── utils.js            # Common utilities
+├── template.yaml               # AWS SAM template
+├── package.json                # Node.js dependencies
+├── test-payloads.json          # Sample test data
+├── test-api.sh                 # API test script
+└── README.md                   # This file
+```
+
+## 🔧 Local Development
+
+To test locally without deploying to AWS:
+
+1. Start your OpenTelemetry backend (e.g., Jaeger)
+2. Use AWS SAM Local:
+
+```bash
+sam build
+sam local start-api --env-vars env.json
+```
+
+Create `env.json`:
+```json
+{
+  "Parameters": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "INVENTORY_SERVICE_URL": "http://host.docker.internal:3000/inventory",
+    "PAYMENT_SERVICE_URL": "http://host.docker.internal:3000/payment"
+  }
+}
+```
+
+## 📊 Observability Best Practices
+
+This demo demonstrates several observability best practices:
+
+1. **Structured Logging** - Logs include trace context for correlation
+2. **Semantic Attributes** - Meaningful span attributes for filtering and analysis
+3. **Error Handling** - Errors are captured as span events
+4. **Business Context** - Business-relevant data in spans (order IDs, amounts, etc.)
+5. **Service Naming** - Clear service names for easy identification
+6. **Context Propagation** - W3C standard trace context across service boundaries
+
+## 🔐 Security Considerations
+
+- This is a demo project - do not use in production without proper security hardening
+- Implement proper authentication/authorization for API endpoints
+- Secure OpenTelemetry Collector endpoints
+- Use AWS Secrets Manager for sensitive configuration
+- Enable API Gateway throttling and request validation
+
+## 🤝 Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+## 📄 License
+
+MIT License - See LICENSE file for details
+
+## 🎓 Learning Resources
+
+- [OpenTelemetry Documentation](https://opentelemetry.io/docs/)
+- [AWS Lambda Best Practices](https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html)
+- [W3C Trace Context](https://www.w3.org/TR/trace-context/)
+- [Distributed Tracing Guide](https://opentelemetry.io/docs/concepts/signals/traces/)
+
+## 🐛 Troubleshooting
+
+### Traces not appearing in backend
+
+- Verify OTEL_EXPORTER_OTLP_ENDPOINT is correctly configured
+- Check Lambda logs in CloudWatch for errors
+- Ensure OpenTelemetry Collector/backend is running and accessible
+- Verify network connectivity between Lambda and collector
+
+### Service-to-service calls failing
+
+- Check that service URLs are correctly configured
+- Verify API Gateway endpoints are deployed
+- Review Lambda function logs for errors
+- Check IAM permissions if using private endpoints
+
+### High latency or timeouts
+
+- Increase Lambda timeout in template.yaml
+- Check OpenTelemetry Collector performance
+- Consider using asynchronous export
+- Review batch span processor configuration
diff --git a/.aws-sam/build/OrderServiceFunction/docker-compose.yaml b/.aws-sam/build/OrderServiceFunction/docker-compose.yaml
new file mode 100644
index 0000000..7f969f4
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/docker-compose.yaml
@@ -0,0 +1,37 @@
+version: '3.8'
+
+services:
+  # Jaeger all-in-one with OTLP support
+  jaeger:
+    image: jaegertracing/all-in-one:latest
+    container_name: jaeger-otel
+    environment:
+      - COLLECTOR_OTLP_ENABLED=true
+      - LOG_LEVEL=debug
+    ports:
+      - "16686:16686"  # Jaeger UI
+      - "4318:4318"    # OTLP HTTP receiver
+      - "4317:4317"    # OTLP gRPC receiver
+      - "14268:14268"  # Jaeger collector HTTP
+      - "14250:14250"  # Jaeger collector gRPC
+    networks:
+      - otel-demo
+
+  # Optional: OpenTelemetry Collector (if you want to use a separate collector)
+  # otel-collector:
+  #   image: otel/opentelemetry-collector-contrib:latest
+  #   container_name: otel-collector
+  #   command: ["--config=/etc/otel-collector-config.yaml"]
+  #   volumes:
+  #     - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+  #   ports:
+  #     - "4318:4318"    # OTLP HTTP receiver
+  #     - "4317:4317"    # OTLP gRPC receiver
+  #     - "8888:8888"    # Prometheus metrics
+  #     - "13133:13133"  # Health check
+  #   networks:
+  #     - otel-demo
+
+networks:
+  otel-demo:
+    driver: bridge
diff --git a/.aws-sam/build/OrderServiceFunction/env.json b/.aws-sam/build/OrderServiceFunction/env.json
new file mode 100644
index 0000000..67b70e4
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/env.json
@@ -0,0 +1,16 @@
+{
+  "OrderServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local",
+    "INVENTORY_SERVICE_URL": "http://127.0.0.1:3001/inventory",
+    "PAYMENT_SERVICE_URL": "http://127.0.0.1:3002/payment"
+  },
+  "InventoryServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  },
+  "PaymentServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  }
+}
diff --git a/.aws-sam/build/OrderServiceFunction/local-test.sh b/.aws-sam/build/OrderServiceFunction/local-test.sh
new file mode 100755
index 0000000..8b43c30
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/local-test.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Simple local testing script using SAM Local
+# This script starts SAM local API and runs tests
+
+set -e
+
+echo "Starting Lambda OpenTelemetry Demo Local Test"
+echo "=============================================="
+echo ""
+
+# Check if Docker is running
+if ! docker info > /dev/null 2>&1; then
+    echo "Error: Docker is not running. Please start Docker first."
+    exit 1
+fi
+
+# Check if Jaeger is running
+if ! docker ps | grep -q jaeger-otel; then
+    echo "Starting Jaeger..."
+    docker-compose up -d jaeger
+    echo "Waiting for Jaeger to be ready..."
+    sleep 5
+else
+    echo "Jaeger is already running"
+fi
+
+echo ""
+echo "Jaeger UI available at: http://localhost:16686"
+echo ""
+
+# Build the Lambda functions
+echo "Building Lambda functions..."
+sam build
+
+if [ $? -ne 0 ]; then
+    echo "Error: Build failed"
+    exit 1
+fi
+
+echo ""
+echo "Lambda functions built successfully!"
+echo ""
+echo "To test the API:"
+echo "1. Start SAM local API in one terminal:"
+echo "   sam local start-api --env-vars env.json"
+echo ""
+echo "2. In another terminal, run the test script:"
+echo "   ./test-api.sh http://127.0.0.1:3000"
+echo ""
+echo "3. View traces in Jaeger UI:"
+echo "   http://localhost:16686"
+echo ""
diff --git a/.aws-sam/build/OrderServiceFunction/package-lock.json b/.aws-sam/build/OrderServiceFunction/package-lock.json
new file mode 100644
index 0000000..eeb2106
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/package-lock.json
@@ -0,0 +1,295 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "lambda-opentelemetry-demo",
+      "version": "1.0.0",
+      "license": "MIT",
+      "dependencies": {
+        "axios": "^1.13.5"
+      }
+    },
+    "node_modules/asynckit": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
+      "license": "MIT"
+    },
+    "node_modules/axios": {
+      "version": "1.13.5",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.13.5.tgz",
+      "integrity": "sha512-cz4ur7Vb0xS4/KUN0tPWe44eqxrIu31me+fbang3ijiNscE129POzipJJA6zniq2C/Z6sJCjMimjS8Lc/GAs8Q==",
+      "license": "MIT",
+      "dependencies": {
+        "follow-redirects": "^1.15.11",
+        "form-data": "^4.0.5",
+        "proxy-from-env": "^1.1.0"
+      }
+    },
+    "node_modules/call-bind-apply-helpers": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
+      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/combined-stream": {
+      "version": "1.0.8",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "license": "MIT",
+      "dependencies": {
+        "delayed-stream": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
+    "node_modules/delayed-stream": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
+      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
+    "node_modules/dunder-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
+      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "gopd": "^1.2.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-define-property": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
+      "integrity": "sha512-e3nRfgfUZ4rNGL232gUgX06QNyyez04KdjFrF+LTRoOXmrOgFKDg4BCdsjW8EnT69eqdYGmRpJwiPVYNrCaW3g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-errors": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
+      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-object-atoms": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.1.tgz",
+      "integrity": "sha512-FGgH2h8zKNim9ljj7dankFPcICIK9Cp5bm+c2gQSYePhpaG5+esrLODihIorn+Pe6FGJzWhXQotPv73jTaldXA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-set-tostringtag": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/es-set-tostringtag/-/es-set-tostringtag-2.1.0.tgz",
+      "integrity": "sha512-j6vWzfrGVfyXxge+O0x5sh6cvxAog0a/4Rdd2K36zCMV5eJ+/+tOAngRO8cODMNWbVRdVlmGZQL2YS3yR8bIUA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "get-intrinsic": "^1.2.6",
+        "has-tostringtag": "^1.0.2",
+        "hasown": "^2.0.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/follow-redirects": {
+      "version": "1.15.11",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.11.tgz",
+      "integrity": "sha512-deG2P0JfjrTxl50XGCDyfI97ZGVCxIpfKYmfyrQ54n5FO/0gfIES8C/Psl6kWVDolizcaaxZJnTS0QSMxvnsBQ==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/form-data": {
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.5.tgz",
+      "integrity": "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==",
+      "license": "MIT",
+      "dependencies": {
+        "asynckit": "^0.4.0",
+        "combined-stream": "^1.0.8",
+        "es-set-tostringtag": "^2.1.0",
+        "hasown": "^2.0.2",
+        "mime-types": "^2.1.12"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/function-bind": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
+      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-intrinsic": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
+      "integrity": "sha512-9fSjSaos/fRIVIp+xSJlE6lfwhES7LNtKaCBIamHsjr2na1BiABJPo0mOjjz8GJDURarmCPGqaiVg5mfjb98CQ==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.2",
+        "es-define-property": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "es-object-atoms": "^1.1.1",
+        "function-bind": "^1.1.2",
+        "get-proto": "^1.0.1",
+        "gopd": "^1.2.0",
+        "has-symbols": "^1.1.0",
+        "hasown": "^2.0.2",
+        "math-intrinsics": "^1.1.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
+      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
+      "license": "MIT",
+      "dependencies": {
+        "dunder-proto": "^1.0.1",
+        "es-object-atoms": "^1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/gopd": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
+      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-symbols": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.1.0.tgz",
+      "integrity": "sha512-1cDNdwJ2Jaohmb3sg4OmKaMBwuC48sYni5HUw2DvsC8LjGTLK9h+eb1X6RyuOHe4hT0ULCW68iomhjUoKUqlPQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-tostringtag": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/has-tostringtag/-/has-tostringtag-1.0.2.tgz",
+      "integrity": "sha512-NqADB8VjPFLM2V0VvHUewwwsw0ZWBaIdgo+ieHtK3hasLz4qeCRjYcqfB6AQrBggRKppKF8L52/VqdVsO47Dlw==",
+      "license": "MIT",
+      "dependencies": {
+        "has-symbols": "^1.0.3"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/hasown": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.2.tgz",
+      "integrity": "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/math-intrinsics": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
+      "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/mime-db": {
+      "version": "1.52.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
+      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/mime-types": {
+      "version": "2.1.35",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
+      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/proxy-from-env": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
+      "integrity": "sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==",
+      "license": "MIT"
+    }
+  }
+}
diff --git a/.aws-sam/build/OrderServiceFunction/package.json b/.aws-sam/build/OrderServiceFunction/package.json
new file mode 100644
index 0000000..abe61a7
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/package.json
@@ -0,0 +1,23 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "description": "Sample AWS Lambda project demonstrating OpenTelemetry integration without CloudWatch/X-Ray",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"No tests specified\" && exit 0",
+    "deploy": "sam deploy --guided",
+    "build": "sam build"
+  },
+  "keywords": [
+    "aws",
+    "lambda",
+    "opentelemetry",
+    "tracing",
+    "nodejs"
+  ],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "axios": "^1.13.5"
+  }
+}
diff --git a/.aws-sam/build/OrderServiceFunction/src/inventory-service/index.js b/.aws-sam/build/OrderServiceFunction/src/inventory-service/index.js
new file mode 100644
index 0000000..7cb0b00
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/src/inventory-service/index.js
@@ -0,0 +1,143 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock inventory database
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  'item-004': { name: 'Monitor', quantity: 5 },
+  'item-005': { name: 'Headphones', quantity: 0 }, // Out of stock
+};
+
+/**
+ * Inventory Service Lambda Handler
+ * This service checks if requested items are available in inventory
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Inventory Service received event:', JSON.stringify(event));
+
+  return withSpan('check-inventory', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, items } = body;
+
+      // Validate input
+      if (!orderId || !items || !Array.isArray(items)) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing or invalid required fields',
+        });
+        return createResponse(400, {
+          available: false,
+          error: 'Missing or invalid required fields: orderId, items (array)',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'inventory.items.count': items.length,
+      });
+
+      console.log(`Checking inventory for order ${orderId}`);
+
+      // Check each item
+      const unavailableItems = [];
+      let allAvailable = true;
+
+      for (const item of items) {
+        const { itemId, quantity } = item;
+        
+        if (!itemId || !quantity) {
+          continue;
+        }
+
+        addSpanAttributes({
+          [`inventory.item.${itemId}.requested`]: quantity,
+        });
+
+        // Check if item exists in inventory
+        if (!inventory[itemId]) {
+          console.log(`Item ${itemId} not found in inventory`);
+          unavailableItems.push({
+            itemId,
+            reason: 'Item not found',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'not-found',
+          });
+          continue;
+        }
+
+        const availableQuantity = inventory[itemId].quantity;
+        addSpanAttributes({
+          [`inventory.item.${itemId}.available`]: availableQuantity,
+        });
+
+        // Check if sufficient quantity is available
+        if (availableQuantity < quantity) {
+          console.log(`Insufficient quantity for item ${itemId}. Requested: ${quantity}, Available: ${availableQuantity}`);
+          unavailableItems.push({
+            itemId,
+            name: inventory[itemId].name,
+            requestedQuantity: quantity,
+            availableQuantity: availableQuantity,
+            reason: availableQuantity === 0 ? 'Out of stock' : 'Insufficient quantity',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'insufficient',
+          });
+        } else {
+          console.log(`Item ${itemId} is available. Requested: ${quantity}, Available: ${availableQuantity}`);
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'available',
+          });
+        }
+      }
+
+      addSpanAttributes({
+        'inventory.all_available': allAvailable,
+        'inventory.unavailable_count': unavailableItems.length,
+      });
+
+      if (allAvailable) {
+        console.log(`All items available for order ${orderId}`);
+        
+        return createResponse(200, {
+          available: true,
+          orderId,
+          message: 'All items are available',
+        });
+      } else {
+        console.log(`Some items unavailable for order ${orderId}:`, unavailableItems);
+        addSpanAttributes({
+          'inventory.failure_reason': 'items-unavailable',
+        });
+        
+        return createResponse(200, {
+          available: false,
+          orderId,
+          unavailableItems,
+          message: 'Some items are not available',
+        });
+      }
+
+    } catch (error) {
+      console.error('Inventory check error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        available: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/OrderServiceFunction/src/order-service/index.js b/.aws-sam/build/OrderServiceFunction/src/order-service/index.js
new file mode 100644
index 0000000..7d05578
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/src/order-service/index.js
@@ -0,0 +1,181 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { callService, createResponse } = require('../shared/utils');
+
+/**
+ * Order Service Lambda Handler
+ * This service accepts orders and orchestrates calls to Inventory and Payment services
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Order Service received event:', JSON.stringify(event));
+
+  return withSpan('process-order', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, items, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !items || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, items, paymentMethod',
+        });
+      }
+
+      // Add order details to span
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'order.items.count': items.length,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing order ${orderId} for customer ${customerId}`);
+
+      // Step 1: Check inventory
+      console.log('Step 1: Checking inventory');
+      const inventoryUrl = process.env.INVENTORY_SERVICE_URL || 'http://localhost:3001/inventory';
+      
+      let inventoryResult;
+      try {
+        inventoryResult = await withSpan('check-inventory', async (inventorySpan) => {
+          addSpanAttributes({
+            'service': 'inventory',
+            'order.id': orderId,
+          });
+          
+          const result = await callService(inventoryUrl, {
+            orderId,
+            items,
+          });
+          
+          addSpanAttributes({
+            'inventory.available': result.available,
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Inventory check failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Inventory check failed',
+          details: error.message,
+        });
+      }
+
+      if (!inventoryResult.available) {
+        addSpanAttributes({
+          'inventory.status': 'out-of-stock',
+          'inventory.unavailable_items': JSON.stringify(inventoryResult.unavailableItems || []),
+        });
+        
+        console.log(`Order ${orderId} failed: Items out of stock`);
+        return createResponse(409, {
+          success: false,
+          orderId,
+          error: 'Items out of stock',
+          unavailableItems: inventoryResult.unavailableItems,
+        });
+      }
+
+      addSpanAttributes({ 'inventory.status': 'available' });
+
+      // Step 2: Process payment
+      console.log('Step 2: Processing payment');
+      const paymentUrl = process.env.PAYMENT_SERVICE_URL || 'http://localhost:3002/payment';
+      
+      let paymentResult;
+      try {
+        paymentResult = await withSpan('process-payment', async (paymentSpan) => {
+          const totalAmount = items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
+          
+          addSpanAttributes({
+            'service': 'payment',
+            'order.id': orderId,
+            'payment.method': paymentMethod,
+            'payment.amount': totalAmount,
+          });
+          
+          const result = await callService(paymentUrl, {
+            orderId,
+            customerId,
+            amount: totalAmount,
+            paymentMethod,
+          });
+          
+          addSpanAttributes({
+            'payment.success': result.success,
+            'payment.transaction_id': result.transactionId || 'none',
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Payment processing failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Payment processing failed',
+          details: error.message,
+        });
+      }
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.status': 'failed',
+          'payment.failure_reason': paymentResult.reason || 'unknown',
+        });
+        
+        console.log(`Order ${orderId} failed: Payment failed`);
+        return createResponse(402, {
+          success: false,
+          orderId,
+          error: 'Payment failed',
+          reason: paymentResult.reason,
+        });
+      }
+
+      addSpanAttributes({
+        'payment.status': 'success',
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      // Order successful
+      console.log(`Order ${orderId} completed successfully`);
+      
+      return createResponse(200, {
+        success: true,
+        orderId,
+        message: 'Order processed successfully',
+        transactionId: paymentResult.transactionId,
+        totalAmount: items.reduce((sum, item) => sum + (item.price * item.quantity), 0),
+      });
+
+    } catch (error) {
+      console.error('Order processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/OrderServiceFunction/src/payment-service/index.js b/.aws-sam/build/OrderServiceFunction/src/payment-service/index.js
new file mode 100644
index 0000000..6a88ea6
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/src/payment-service/index.js
@@ -0,0 +1,144 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock payment processing
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  'expired-card': ['4333333333333333', 'expired-card'],
+};
+
+/**
+ * Simulate payment processing with some failure scenarios
+ * @param {string} paymentMethod - Payment method identifier
+ * @param {number} amount - Payment amount
+ * @returns {Object} Payment result
+ */
+function processPayment(paymentMethod, amount) {
+  // Check for known failure patterns
+  for (const [reason, patterns] of Object.entries(FAILURE_PATTERNS)) {
+    if (patterns.some(pattern => paymentMethod.includes(pattern))) {
+      return {
+        success: false,
+        reason: reason.replace('-', ' '),
+        transactionId: null,
+      };
+    }
+  }
+
+  // Simulate random failures (10% chance)
+  if (Math.random() < 0.1) {
+    const reasons = ['network-timeout', 'gateway-error', 'rate-limit-exceeded'];
+    const randomReason = reasons[Math.floor(Math.random() * reasons.length)];
+    return {
+      success: false,
+      reason: randomReason.replace('-', ' '),
+      transactionId: null,
+    };
+  }
+
+  // Successful payment
+  return {
+    success: true,
+    transactionId: `txn-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`,
+  };
+}
+
+/**
+ * Payment Service Lambda Handler
+ * This service processes payments with failure scenarios for testing
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Payment Service received event:', JSON.stringify(event));
+
+  return withSpan('process-payment', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, amount, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !amount || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, amount, paymentMethod',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'payment.amount': amount,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing payment for order ${orderId}, amount: ${amount}`);
+
+      // Validate amount
+      if (amount <= 0) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Invalid payment amount',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Invalid payment amount',
+        });
+      }
+
+      // Process payment
+      const paymentResult = processPayment(paymentMethod, amount);
+
+      addSpanAttributes({
+        'payment.success': paymentResult.success,
+      });
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.failure_reason': paymentResult.reason,
+        });
+        
+        console.log(`Payment failed for order ${orderId}: ${paymentResult.reason}`);
+        
+        return createResponse(200, {
+          success: false,
+          orderId,
+          reason: paymentResult.reason,
+          message: 'Payment processing failed',
+        });
+      }
+
+      addSpanAttributes({
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      console.log(`Payment successful for order ${orderId}. Transaction ID: ${paymentResult.transactionId}`);
+
+      return createResponse(200, {
+        success: true,
+        orderId,
+        transactionId: paymentResult.transactionId,
+        amount,
+        message: 'Payment processed successfully',
+      });
+
+    } catch (error) {
+      console.error('Payment processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/OrderServiceFunction/src/shared/tracer.js b/.aws-sam/build/OrderServiceFunction/src/shared/tracer.js
new file mode 100644
index 0000000..3cedef5
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/src/shared/tracer.js
@@ -0,0 +1,118 @@
+// When using OpenTelemetry Lambda Layer with auto-instrumentation,
+// the @opentelemetry/api is provided by the layer at /opt/nodejs/node_modules
+const api = require('@opentelemetry/api');
+
+/**
+ * Get the current active span
+ * The Lambda Layer automatically creates spans for Lambda invocations
+ * @returns {Span} Current active span
+ */
+function getCurrentSpan() {
+  return api.trace.getActiveSpan();
+}
+
+/**
+ * Get a tracer instance
+ * @param {string} name - Tracer name (usually service name)
+ * @param {string} version - Service version
+ * @returns {Tracer} OpenTelemetry tracer instance
+ */
+function getTracer(name = 'lambda-app', version = '1.0.0') {
+  return api.trace.getTracer(name, version);
+}
+
+/**
+ * Create a new span for a specific operation
+ * @param {string} spanName - Name of the span
+ * @param {Function} fn - Function to execute within the span
+ * @param {Object} attributes - Optional span attributes
+ * @returns {Promise} Result of the function execution
+ */
+async function withSpan(spanName, fn, attributes = {}) {
+  const tracer = getTracer();
+  return tracer.startActiveSpan(spanName, async (span) => {
+    try {
+      // Add custom attributes
+      Object.entries(attributes).forEach(([key, value]) => {
+        span.setAttribute(key, value);
+      });
+      
+      const result = await fn(span);
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.setStatus({
+        code: api.SpanStatusCode.ERROR,
+        message: error.message,
+      });
+      span.recordException(error);
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+}
+
+/**
+ * Add custom attributes to the current span
+ * @param {Object} attributes - Key-value pairs of attributes to add
+ */
+function addSpanAttributes(attributes) {
+  const span = getCurrentSpan();
+  if (span) {
+    Object.entries(attributes).forEach(([key, value]) => {
+      if (value !== null && value !== undefined) {
+        span.setAttribute(key, value);
+      }
+    });
+  }
+}
+
+/**
+ * Record an exception on the current span
+ * @param {Error} error - Error to record
+ */
+function recordException(error) {
+  const span = getCurrentSpan();
+  if (span) {
+    span.recordException(error);
+    span.setStatus({
+      code: api.SpanStatusCode.ERROR,
+      message: error.message,
+    });
+  }
+}
+
+/**
+ * Inject trace context into headers for downstream service calls
+ * Uses W3C Trace Context propagation
+ * @returns {Object} Headers with trace context
+ */
+function injectTraceContext() {
+  const headers = {};
+  const span = getCurrentSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    if (spanContext && spanContext.traceId && spanContext.spanId) {
+      // W3C Trace Context format
+      const traceFlags = spanContext.traceFlags || 0;
+      headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-${traceFlags.toString(16).padStart(2, '0')}`;
+      
+      if (spanContext.traceState) {
+        headers.tracestate = spanContext.traceState.serialize();
+      }
+    }
+  }
+  
+  return headers;
+}
+
+module.exports = {
+  getTracer,
+  getCurrentSpan,
+  withSpan,
+  addSpanAttributes,
+  recordException,
+  injectTraceContext,
+};
diff --git a/.aws-sam/build/OrderServiceFunction/src/shared/utils.js b/.aws-sam/build/OrderServiceFunction/src/shared/utils.js
new file mode 100644
index 0000000..2da73e3
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/src/shared/utils.js
@@ -0,0 +1,61 @@
+const axios = require('axios');
+const { injectTraceContext } = require('./tracer');
+
+/**
+ * Make an HTTP request to another Lambda service with trace context propagation
+ * @param {string} url - Service URL
+ * @param {Object} data - Request payload
+ * @param {string} method - HTTP method (default: POST)
+ * @returns {Promise<Object>} Response data
+ */
+async function callService(url, data, method = 'POST') {
+  // Inject trace context into headers
+  const headers = {
+    'Content-Type': 'application/json',
+    ...injectTraceContext(),
+  };
+
+  console.log(`Calling service: ${url} with method: ${method}`);
+  console.log(`Trace context headers:`, headers);
+
+  try {
+    const response = await axios({
+      method,
+      url,
+      data,
+      headers,
+    });
+
+    console.log(`Service call successful: ${url}`);
+    return response.data;
+  } catch (error) {
+    console.error(`Service call failed: ${url}`, error.message);
+    if (error.response) {
+      throw new Error(`Service call failed: ${error.response.status} - ${JSON.stringify(error.response.data)}`);
+    }
+    throw error;
+  }
+}
+
+/**
+ * Create a Lambda response object
+ * @param {number} statusCode - HTTP status code
+ * @param {Object} body - Response body
+ * @param {Object} headers - Additional headers
+ * @returns {Object} Lambda response object
+ */
+function createResponse(statusCode, body, headers = {}) {
+  return {
+    statusCode,
+    headers: {
+      'Content-Type': 'application/json',
+      ...headers,
+    },
+    body: JSON.stringify(body),
+  };
+}
+
+module.exports = {
+  callService,
+  createResponse,
+};
diff --git a/.aws-sam/build/OrderServiceFunction/template.yaml b/.aws-sam/build/OrderServiceFunction/template.yaml
new file mode 100644
index 0000000..bc11944
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/template.yaml
@@ -0,0 +1,137 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: Lambda OpenTelemetry Demo - Order, Inventory, and Payment Services with AWS ADOT Layer
+
+Globals:
+  Function:
+    Timeout: 30
+    MemorySize: 512
+    Runtime: nodejs20.x
+    Environment:
+      Variables:
+        AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+        OTEL_SERVICE_NAME: will-be-overridden
+        OTEL_TRACES_SAMPLER: AlwaysOn
+        OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+        OTEL_EXPORTER_OTLP_ENDPOINT: !Ref OtelCollectorEndpoint
+        OTEL_PROPAGATORS: tracecontext
+        OTEL_RESOURCE_ATTRIBUTES: !Sub deployment.environment=${Environment}
+
+Parameters:
+  OtelCollectorEndpoint:
+    Type: String
+    Default: 'http://localhost:4318'
+    Description: OpenTelemetry Collector endpoint URL (without /v1/traces path)
+  
+  Environment:
+    Type: String
+    Default: 'production'
+    Description: Deployment environment (e.g., development, staging, production)
+  
+  AdotLayerArn:
+    Type: String
+    Default: 'arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5'
+    Description: |
+      ARN of the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for Node.js.
+      Find the latest ARN for your region at:
+      https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Resources:
+  # Order Service Function
+  OrderServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: order-service
+      CodeUri: ./
+      Handler: src/order-service/index.handler
+      Description: Order Service - Orchestrates order processing
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: order-service
+          INVENTORY_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+          PAYMENT_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+      Events:
+        OrderApi:
+          Type: Api
+          Properties:
+            Path: /order
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Inventory Service Function
+  InventoryServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: inventory-service
+      CodeUri: ./
+      Handler: src/inventory-service/index.handler
+      Description: Inventory Service - Checks item availability
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: inventory-service
+      Events:
+        InventoryApi:
+          Type: Api
+          Properties:
+            Path: /inventory
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Payment Service Function
+  PaymentServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: payment-service
+      CodeUri: ./
+      Handler: src/payment-service/index.handler
+      Description: Payment Service - Processes payments
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: payment-service
+      Events:
+        PaymentApi:
+          Type: Api
+          Properties:
+            Path: /payment
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # API Gateway
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+      Description: API Gateway for Lambda OpenTelemetry Demo
+
+Outputs:
+  ApiEndpoint:
+    Description: API Gateway endpoint URL
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod'
+  
+  OrderServiceUrl:
+    Description: Order Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/order'
+    
+  InventoryServiceUrl:
+    Description: Inventory Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+    
+  PaymentServiceUrl:
+    Description: Payment Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+  
+  AdotLayerVersion:
+    Description: ADOT Lambda Layer ARN being used
+    Value: !Ref AdotLayerArn
diff --git a/.aws-sam/build/OrderServiceFunction/test-api.sh b/.aws-sam/build/OrderServiceFunction/test-api.sh
new file mode 100755
index 0000000..680b864
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/test-api.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+
+# Color codes for output
+GREEN='\033[0;32m'
+BLUE='\033[0;34m'
+YELLOW='\033[1;33m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+echo -e "${BLUE}========================================${NC}"
+echo -e "${BLUE}Lambda OpenTelemetry Demo - Test Script${NC}"
+echo -e "${BLUE}========================================${NC}"
+echo ""
+
+# Check if API endpoint is provided
+if [ -z "$1" ]; then
+    echo -e "${RED}Error: API endpoint is required${NC}"
+    echo "Usage: ./test-api.sh <API_ENDPOINT>"
+    echo "Example: ./test-api.sh https://abc123.execute-api.us-east-1.amazonaws.com/Prod"
+    exit 1
+fi
+
+API_ENDPOINT=$1
+ORDER_URL="${API_ENDPOINT}/order"
+
+echo -e "${YELLOW}Using API Endpoint: ${API_ENDPOINT}${NC}"
+echo ""
+
+# Test 1: Successful Order
+echo -e "${BLUE}Test 1: Successful Order${NC}"
+echo "Testing with items that are in stock and valid payment method..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 2: Out of Stock Order
+echo -e "${BLUE}Test 2: Out of Stock Order${NC}"
+echo "Testing with items that are out of stock..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 3: Payment Failure (Card Declined)
+echo -e "${BLUE}Test 3: Payment Failure - Card Declined${NC}"
+echo "Testing with a payment method that will be declined..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 4: Payment Failure (Insufficient Funds)
+echo -e "${BLUE}Test 4: Payment Failure - Insufficient Funds${NC}"
+echo "Testing with insufficient funds scenario..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+echo -e "${GREEN}========================================${NC}"
+echo -e "${GREEN}All tests completed!${NC}"
+echo -e "${GREEN}Check your OpenTelemetry backend to view the traces${NC}"
+echo -e "${GREEN}========================================${NC}"
diff --git a/.aws-sam/build/OrderServiceFunction/test-payloads.json b/.aws-sam/build/OrderServiceFunction/test-payloads.json
new file mode 100644
index 0000000..603d30c
--- /dev/null
+++ b/.aws-sam/build/OrderServiceFunction/test-payloads.json
@@ -0,0 +1,66 @@
+{
+  "successfulOrder": {
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  },
+  "outOfStockOrder": {
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  },
+  "paymentFailureOrder": {
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  },
+  "insufficientFundsOrder": {
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }
+}
diff --git a/.aws-sam/build/PaymentServiceFunction/.env.example b/.aws-sam/build/PaymentServiceFunction/.env.example
new file mode 100644
index 0000000..3f3aa74
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/.env.example
@@ -0,0 +1,7 @@
+# OpenTelemetry Configuration
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318/v1/traces
+ENVIRONMENT=development
+
+# Service URLs (for local testing)
+INVENTORY_SERVICE_URL=http://localhost:3001/inventory
+PAYMENT_SERVICE_URL=http://localhost:3002/payment
diff --git a/.aws-sam/build/PaymentServiceFunction/ADOT-LAYER-CONFIG.md b/.aws-sam/build/PaymentServiceFunction/ADOT-LAYER-CONFIG.md
new file mode 100644
index 0000000..cffddc9
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/ADOT-LAYER-CONFIG.md
@@ -0,0 +1,366 @@
+# AWS ADOT Lambda Layer Configuration Guide
+
+This document explains how to configure and use the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for automatic instrumentation.
+
+## Overview
+
+The AWS ADOT Lambda Layer provides automatic OpenTelemetry instrumentation for Lambda functions without requiring you to bundle OpenTelemetry SDKs in your deployment package.
+
+## Layer ARNs by Region
+
+### Node.js 18.x ADOT Layer ARNs (Latest: v1-18-1)
+
+| Region | ARN |
+|--------|-----|
+| us-east-1 | `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-east-2 | `arn:aws:lambda:us-east-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-1 | `arn:aws:lambda:us-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-2 | `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-west-1 | `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-central-1 | `arn:aws:lambda:eu-central-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-southeast-1 | `arn:aws:lambda:ap-southeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-northeast-1 | `arn:aws:lambda:ap-northeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+
+**Find the latest ARNs**: https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+## Required Environment Variables
+
+### Essential Configuration
+
+```yaml
+Environment:
+  Variables:
+    # Enable ADOT auto-instrumentation wrapper
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+    
+    # Service name for identification in traces
+    OTEL_SERVICE_NAME: your-service-name
+    
+    # Sampling configuration (AlwaysOn for demo, adjust for production)
+    OTEL_TRACES_SAMPLER: AlwaysOn
+    
+    # Protocol for OTLP export
+    OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+    
+    # OpenTelemetry Collector endpoint (without /v1/traces)
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://your-collector:4318
+    
+    # Trace context propagation format
+    OTEL_PROPAGATORS: tracecontext
+```
+
+### Advanced Configuration Options
+
+```yaml
+Environment:
+  Variables:
+    # Resource attributes (for environment, version, etc.)
+    OTEL_RESOURCE_ATTRIBUTES: deployment.environment=production,service.version=1.0.0
+    
+    # Specific endpoint for traces (optional, overrides OTEL_EXPORTER_OTLP_ENDPOINT)
+    OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: http://your-collector:4318/v1/traces
+    
+    # Enable/disable specific instrumentations
+    OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: true
+    OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+    
+    # Span attribute limits
+    OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT: 4095
+    OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 128
+```
+
+## Exporter Backends
+
+### 1. Jaeger (Local Development)
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://localhost:4318
+OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+```
+
+Run Jaeger with OTLP support:
+```bash
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+```
+
+### 2. AWS X-Ray (with ADOT Collector)
+
+If you want to send traces to AWS X-Ray, deploy an ADOT Collector in your VPC:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://adot-collector:4318
+OTEL_PROPAGATORS: tracecontext,xray
+```
+
+ADOT Collector configuration:
+```yaml
+receivers:
+  otlp:
+    protocols:
+      http:
+        endpoint: 0.0.0.0:4318
+
+exporters:
+  awsxray:
+    region: us-east-1
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      exporters: [awsxray]
+```
+
+### 3. Grafana Cloud / Honeycomb / DataDog
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: https://your-saas-endpoint
+OTEL_EXPORTER_OTLP_HEADERS: Authorization=Bearer your-api-key
+```
+
+### 4. Self-Hosted OpenTelemetry Collector
+
+Deploy a collector in your VPC or use Lambda Extension:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+## How Auto-Instrumentation Works
+
+### 1. Wrapper Execution
+
+The `AWS_LAMBDA_EXEC_WRAPPER` environment variable points to `/opt/otel-handler`, which:
+- Initializes the OpenTelemetry SDK before your handler
+- Automatically instruments common libraries (http, https, aws-sdk, etc.)
+- Creates a root span for each Lambda invocation
+- Propagates trace context from incoming requests
+
+### 2. Automatic Instrumentation
+
+The layer automatically instruments:
+- ✅ AWS SDK calls
+- ✅ HTTP/HTTPS requests (axios, node-fetch, http, https)
+- ✅ Lambda invocation (creates root span)
+- ✅ Downstream service calls with trace context propagation
+
+### 3. Context Propagation
+
+The layer automatically:
+- Extracts W3C trace context from incoming API Gateway requests
+- Injects trace context into outgoing HTTP requests
+- Maintains trace context across async operations
+
+## Usage in Your Code
+
+### Basic Usage (Automatic)
+
+With the layer configured, your Lambda function is automatically instrumented:
+
+```javascript
+exports.handler = async (event) => {
+  // Automatically traced!
+  const response = await axios.get('https://api.example.com');
+  return { statusCode: 200, body: JSON.stringify(response.data) };
+};
+```
+
+### Adding Custom Spans
+
+For additional business logic spans:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service', '1.0.0');
+  
+  return tracer.startActiveSpan('business-operation', async (span) => {
+    try {
+      span.setAttribute('customer.id', event.customerId);
+      
+      // Your business logic
+      const result = await processOrder(event);
+      
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.recordException(error);
+      span.setStatus({ code: api.SpanStatusCode.ERROR });
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+};
+```
+
+### Adding Attributes to Current Span
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const span = api.trace.getActiveSpan();
+  if (span) {
+    span.setAttribute('order.id', event.orderId);
+    span.setAttribute('order.amount', event.amount);
+  }
+  
+  // Your handler logic
+};
+```
+
+## Trace Context Propagation
+
+### Automatic (HTTP Clients)
+
+The layer automatically propagates context for instrumented HTTP clients:
+
+```javascript
+const axios = require('axios');
+
+// Trace context is automatically added to headers!
+const response = await axios.post('https://api.example.com/payment', data);
+```
+
+### Manual (Custom Clients)
+
+For custom HTTP clients or non-instrumented libraries:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+function getTraceHeaders() {
+  const headers = {};
+  const span = api.trace.getActiveSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-01`;
+  }
+  
+  return headers;
+}
+
+// Use in your custom client
+const headers = { ...getTraceHeaders(), 'Content-Type': 'application/json' };
+```
+
+## Sampling
+
+### AlwaysOn (Development/Demo)
+
+```yaml
+OTEL_TRACES_SAMPLER: AlwaysOn
+```
+
+Traces every request. Good for development but expensive in production.
+
+### TraceIdRatioBased (Production)
+
+```yaml
+OTEL_TRACES_SAMPLER: TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1  # 10% sampling
+```
+
+Samples a percentage of requests to reduce costs.
+
+### ParentBased (Recommended)
+
+```yaml
+OTEL_TRACES_SAMPLER: ParentBased_TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1
+```
+
+Respects parent sampling decisions while applying ratio-based sampling to root spans.
+
+## Performance Considerations
+
+### Cold Start Impact
+
+The ADOT layer adds ~200-300ms to cold start time:
+- Layer initialization: ~100ms
+- Auto-instrumentation setup: ~100-200ms
+
+### Runtime Overhead
+
+- Minimal overhead during warm execution (<5ms per invocation)
+- Async span export doesn't block Lambda execution
+- Batching reduces network calls
+
+### Optimization Tips
+
+1. **Use provisioned concurrency** for latency-sensitive functions
+2. **Adjust span limits** to reduce memory usage:
+   ```yaml
+   OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 32
+   OTEL_SPAN_EVENT_COUNT_LIMIT: 32
+   ```
+3. **Use sampling** in high-volume environments
+4. **Disable unused instrumentations**:
+   ```yaml
+   OTEL_INSTRUMENTATION_AWS_LAMBDA_ENABLED: true
+   OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+   OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: false
+   ```
+
+## Troubleshooting
+
+### No Traces Appearing
+
+1. Check CloudWatch Logs for ADOT errors:
+   ```
+   grep "otel" /aws/lambda/your-function
+   ```
+
+2. Verify environment variables:
+   ```bash
+   aws lambda get-function-configuration --function-name your-function \
+     --query 'Environment.Variables'
+   ```
+
+3. Test collector endpoint connectivity:
+   - Ensure Lambda has network access to the collector
+   - Check security groups and NACLs
+   - Verify collector is accepting OTLP HTTP on port 4318
+
+### Wrapper Not Running
+
+Error: `AWS_LAMBDA_EXEC_WRAPPER is set but the wrapper does not exist`
+
+**Solution**: Verify the layer ARN is correct and matches your region.
+
+### Trace Context Not Propagating
+
+1. Ensure `OTEL_PROPAGATORS=tracecontext` is set
+2. Check if HTTP library is supported (axios, node-fetch, http, https)
+3. For unsupported libraries, manually inject headers
+
+### High Cold Start Times
+
+1. Consider using Lambda SnapStart (if available)
+2. Use provisioned concurrency
+3. Minimize layer count (combine layers if possible)
+4. Profile and optimize your application code
+
+## Best Practices
+
+1. **Set meaningful service names**: Use descriptive names that reflect the business function
+2. **Add business context**: Include order IDs, customer IDs, and other relevant attributes
+3. **Handle errors properly**: Record exceptions and set error status on spans
+4. **Use semantic conventions**: Follow OpenTelemetry semantic conventions for consistency
+5. **Monitor collector health**: Ensure your collector is performant and highly available
+6. **Set appropriate sampling**: Balance cost with observability needs
+7. **Use tags for filtering**: Add environment, version, and region as resource attributes
+
+## References
+
+- AWS ADOT Lambda: https://aws-otel.github.io/docs/getting-started/lambda
+- OpenTelemetry Lambda Instrumentation: https://opentelemetry.io/docs/platforms/faas/lambda-auto-instrument/
+- W3C Trace Context: https://www.w3.org/TR/trace-context/
+- OpenTelemetry Semantic Conventions: https://opentelemetry.io/docs/specs/semconv/
diff --git a/.aws-sam/build/PaymentServiceFunction/ARCHITECTURE.md b/.aws-sam/build/PaymentServiceFunction/ARCHITECTURE.md
new file mode 100644
index 0000000..ff7e7c2
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/ARCHITECTURE.md
@@ -0,0 +1,366 @@
+# Architecture Details
+
+## Service Flow
+
+### 1. Successful Order Flow
+
+```
+Client
+  │
+  │ POST /order
+  ├─────────────────────────────────────────┐
+  │                                         │
+  ▼                                         │
+Order Service                               │
+  │                                         │
+  │ 1. Validate request                     │
+  │ 2. Create root span                     │
+  │                                         │
+  │ POST /inventory (with trace context)    │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Inventory Service               │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Check stock levels       │           │
+  │ 4. Return availability      │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: available=true    │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ POST /payment (with trace context)      │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Payment Service                 │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Process payment          │           │
+  │ 4. Return result            │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: success=true      │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ Complete order processing   │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: 200 OK            │           │
+  ▼                             │           │
+Client ◄──────────────────────────────────────┘
+```
+
+### 2. Out of Stock Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Out of stock detected)
+                       ← 
+         Order Service 
+         (Skip payment, return 409)
+       ←
+Client
+```
+
+### 3. Payment Failure Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Items available)
+                       ← 
+         Order Service → Payment Service
+                         (Payment failed)
+                       ←
+         Order Service
+         (Return 402)
+       ←
+Client
+```
+
+## Trace Structure
+
+### Trace Hierarchy
+
+```
+Trace ID: 00000000000000000000000000000001
+│
+└─ Span: process-order (Order Service)
+   │ Duration: 245ms
+   │ Attributes:
+   │   - order.id: ORD-001
+   │   - customer.id: CUST-123
+   │   - order.items.count: 2
+   │
+   ├─ Span: check-inventory (Order Service)
+   │  │ Duration: 15ms
+   │  │ Attributes:
+   │  │   - service: inventory
+   │  │   - order.id: ORD-001
+   │  │
+   │  └─ Span: HTTP POST (Auto-instrumented)
+   │     │ Duration: 12ms
+   │     │
+   │     └─ Span: check-inventory (Inventory Service)
+   │        Duration: 8ms
+   │        Attributes:
+   │          - inventory.available: true
+   │          - inventory.items.count: 2
+   │
+   └─ Span: process-payment (Order Service)
+      │ Duration: 180ms
+      │ Attributes:
+      │   - service: payment
+      │   - order.id: ORD-001
+      │   - payment.method: credit-card-5555
+      │   - payment.amount: 1059.97
+      │
+      └─ Span: HTTP POST (Auto-instrumented)
+         │ Duration: 175ms
+         │
+         └─ Span: process-payment (Payment Service)
+            Duration: 170ms
+            Attributes:
+              - payment.success: true
+              - payment.transaction_id: txn-1234567890-abc123
+```
+
+## OpenTelemetry Components
+
+### 1. Tracer Provider
+
+Manages the lifecycle of tracers and span processors.
+
+```javascript
+const provider = new NodeTracerProvider({
+  resource: resource,
+});
+```
+
+### 2. OTLP Exporter
+
+Exports spans to OpenTelemetry Collector using HTTP.
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: 'http://localhost:4318/v1/traces',
+});
+```
+
+### 3. Batch Span Processor
+
+Batches spans before export for efficiency.
+
+```javascript
+provider.addSpanProcessor(new BatchSpanProcessor(exporter));
+```
+
+### 4. Auto Instrumentations
+
+Automatically instruments common libraries.
+
+```javascript
+registerInstrumentations({
+  instrumentations: [
+    getNodeAutoInstrumentations({
+      '@opentelemetry/instrumentation-http': { enabled: true },
+      '@opentelemetry/instrumentation-https': { enabled: true },
+    }),
+  ],
+});
+```
+
+## Trace Context Propagation
+
+### W3C Trace Context Format
+
+```
+traceparent: 00-<trace-id>-<span-id>-<trace-flags>
+
+Example:
+traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+            │  │                                │                │
+            │  └─ Trace ID (32 hex chars)      │                └─ Flags
+            │                                   └─ Parent Span ID (16 hex chars)
+            └─ Version (00)
+```
+
+### Context Injection
+
+When Order Service calls Inventory Service:
+
+```javascript
+// Order Service
+const headers = injectTraceContext();
+// headers = { traceparent: '00-...-...-01' }
+
+axios.post(inventoryUrl, data, { headers });
+```
+
+### Context Extraction
+
+When Inventory Service receives request:
+
+```javascript
+// Inventory Service
+const traceContext = extractTraceContext(event);
+// Continue the trace with the same trace ID
+```
+
+## Span Attributes
+
+### Semantic Conventions
+
+Following OpenTelemetry semantic conventions:
+
+| Attribute | Description | Example |
+|-----------|-------------|---------|
+| `service.name` | Service identifier | `order-service` |
+| `service.version` | Service version | `1.0.0` |
+| `deployment.environment` | Environment | `production` |
+| `order.id` | Order identifier | `ORD-001` |
+| `customer.id` | Customer identifier | `CUST-123` |
+| `payment.amount` | Payment amount | `1059.97` |
+| `payment.method` | Payment method | `credit-card-5555` |
+| `inventory.available` | Availability flag | `true` |
+| `http.method` | HTTP method | `POST` |
+| `http.status_code` | HTTP status | `200` |
+
+## Error Handling
+
+### Error Span Status
+
+```javascript
+span.setStatus({
+  code: api.SpanStatusCode.ERROR,
+  message: error.message,
+});
+span.recordException(error);
+```
+
+### Business Logic Errors vs Technical Errors
+
+- **Business Logic Errors** (out of stock, payment declined):
+  - Span status: OK
+  - Custom attributes indicate business failure
+  - Example: `inventory.available: false`
+
+- **Technical Errors** (network failure, invalid input):
+  - Span status: ERROR
+  - Exception recorded
+  - Stack trace captured
+
+## Performance Considerations
+
+### Batch Processing
+
+Spans are batched before export to reduce network overhead:
+
+```javascript
+new BatchSpanProcessor(exporter, {
+  maxQueueSize: 2048,
+  maxExportBatchSize: 512,
+  scheduledDelayMillis: 5000,
+})
+```
+
+### Sampling
+
+For high-volume systems, implement sampling:
+
+```javascript
+const sampler = new TraceIdRatioBasedSampler(0.1); // 10% sampling
+const provider = new NodeTracerProvider({
+  resource: resource,
+  sampler: sampler,
+});
+```
+
+### Async Export
+
+Span export is asynchronous and doesn't block Lambda execution.
+
+## Security
+
+### Securing OTLP Endpoint
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
+  headers: {
+    'Authorization': `Bearer ${process.env.OTEL_API_KEY}`,
+  },
+});
+```
+
+### Data Privacy
+
+- Avoid capturing sensitive data in spans
+- Redact PII from span attributes
+- Use attribute filtering in the collector
+
+## Monitoring and Alerting
+
+### Key Metrics to Monitor
+
+1. **Trace Completeness**
+   - Percentage of complete traces
+   - Missing spans
+
+2. **Error Rates**
+   - Spans with ERROR status
+   - Service-specific error rates
+
+3. **Latency**
+   - P50, P95, P99 latencies
+   - Per-service latency breakdown
+
+4. **Business Metrics**
+   - Order success rate
+   - Payment failure rate
+   - Inventory unavailability rate
+
+### Example Queries (Jaeger)
+
+```
+# Find all failed orders
+service="order-service" AND error=true
+
+# Find orders with payment failures
+service="payment-service" AND payment.success=false
+
+# Find slow orders (> 1s)
+service="order-service" AND duration>1000ms
+
+# Find out-of-stock scenarios
+service="inventory-service" AND inventory.available=false
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Traces not appearing**
+   - Check OTLP endpoint connectivity
+   - Verify Lambda has network access
+   - Check CloudWatch logs for export errors
+
+2. **Broken traces**
+   - Verify trace context propagation
+   - Check HTTP header forwarding
+   - Ensure consistent trace ID format
+
+3. **High latency**
+   - Review span processor configuration
+   - Check collector performance
+   - Consider async export optimization
+
+4. **Missing spans**
+   - Verify auto-instrumentation is active
+   - Check for exceptions during span creation
+   - Review sampling configuration
diff --git a/.aws-sam/build/PaymentServiceFunction/README.md b/.aws-sam/build/PaymentServiceFunction/README.md
new file mode 100644
index 0000000..aff152d
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/README.md
@@ -0,0 +1,476 @@
+# Lambda OpenTelemetry Demo
+
+A comprehensive AWS Lambda project demonstrating how to integrate OpenTelemetry for end-to-end distributed tracing across multiple microservices **without using AWS CloudWatch or X-Ray**, using the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation.
+
+## 🎯 Overview
+
+This project implements a realistic e-commerce order processing workflow using three Lambda functions representing distinct microservices:
+
+1. **Order Service** - Orchestrates the order processing workflow
+2. **Inventory Service** - Validates item availability
+3. **Payment Service** - Processes payments
+
+The services communicate with each other while propagating trace context using OpenTelemetry, enabling complete visibility into request flows across all services.
+
+## 🏗️ Architecture
+
+```
+┌─────────────────┐
+│  Order Service  │
+│   (Lambda)      │
+└────────┬────────┘
+         │
+         ├──────────────────┐
+         │                  │
+         ▼                  ▼
+┌─────────────────┐  ┌─────────────────┐
+│ Inventory Svc   │  │  Payment Svc    │
+│   (Lambda)      │  │   (Lambda)      │
+└─────────────────┘  └─────────────────┘
+         │                  │
+         └──────┬───────────┘
+                ▼
+        OpenTelemetry
+         Collector
+                │
+                ▼
+        Tracing Backend
+      (Jaeger/Zipkin/etc)
+```
+
+## ✨ Features
+
+- ✅ **AWS ADOT Lambda Layer** - Uses AWS Distro for OpenTelemetry Lambda Layer for zero-code instrumentation
+- ✅ **Automatic Instrumentation** - Auto-instruments Lambda, HTTP/HTTPS, and AWS SDK without code changes
+- ✅ **Distributed Tracing** - End-to-end trace propagation across Lambda functions
+- ✅ **W3C Trace Context** - Standard trace context propagation using W3C format
+- ✅ **OTLP Export** - Exports traces using OTLP HTTP protocol
+- ✅ **Custom Spans** - Manual span creation for business logic insights
+- ✅ **No CloudWatch/X-Ray** - Direct export to any OpenTelemetry-compatible backend
+- ✅ **Error Scenarios** - Built-in test scenarios for:
+  - Out of stock items
+  - Payment failures (card declined, insufficient funds)
+  - Network errors
+
+## 📋 Prerequisites
+
+- Node.js 18.x or later
+- AWS CLI configured with appropriate credentials
+- AWS SAM CLI for deployment
+- OpenTelemetry Collector or compatible backend (Jaeger, Zipkin, etc.)
+
+## 🚀 Quick Start
+
+### 1. Install Dependencies
+
+```bash
+npm install
+```
+
+### 2. Set Up OpenTelemetry Backend
+
+You need an OpenTelemetry-compatible backend to receive and visualize traces. Here are some options:
+
+#### Option A: Jaeger (Recommended for local testing)
+
+```bash
+# Run Jaeger all-in-one with Docker (or use docker-compose)
+docker-compose up -d jaeger
+
+# Or manually:
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+
+# Access Jaeger UI at http://localhost:16686
+```
+
+#### Option B: Zipkin
+
+```bash
+# Run Zipkin with Docker
+docker run -d --name zipkin \
+  -p 9411:9411 \
+  openzipkin/zipkin:latest
+
+# Note: You'll need an OpenTelemetry Collector to convert OTLP to Zipkin format
+```
+
+#### Option C: Grafana Cloud, Honeycomb, or other SaaS providers
+
+Configure the OTEL_EXPORTER_OTLP_ENDPOINT parameter with your provider's endpoint.
+
+### 3. Update Lambda Layer ARN
+
+**Important**: Update the `AdotLayerArn` parameter in `template.yaml` with the correct ARN for your AWS region.
+
+Find the latest ARN for your region here:
+- https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Example ARNs:
+- **us-east-1**: `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **us-west-2**: `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **eu-west-1**: `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+
+See [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md) for complete list.
+
+### 4. Deploy to AWS
+
+```bash
+# Build the Lambda functions
+sam build
+
+# Deploy (follow the prompts)
+sam deploy --guided
+
+# Note the API endpoint from the outputs
+```
+
+During `sam deploy --guided`, you'll be prompted to provide:
+- **Stack name** (e.g., `lambda-otel-demo`)
+- **AWS Region** (e.g., `us-east-1`)
+- **OtelCollectorEndpoint** - Your OpenTelemetry Collector endpoint without `/v1/traces` (e.g., `http://your-collector:4318`)
+- **Environment** - Deployment environment (e.g., `production`, `staging`)
+- **AdotLayerArn** - AWS ADOT Lambda Layer ARN for your region
+- Confirm changes before deployment
+
+**Note**: If you're using a collector in a VPC, ensure your Lambda functions have VPC access configured.
+
+### 5. Test the Services
+
+Use the provided test script:
+
+```bash
+# Replace with your actual API endpoint from SAM deploy output
+./test-api.sh https://your-api-id.execute-api.region.amazonaws.com/Prod
+```
+
+Or manually test with curl:
+
+```bash
+# Successful order
+curl -X POST https://your-api-endpoint/Prod/order \
+  -H "Content-Type: application/json" \
+  -d @test-payloads.json
+```
+
+### 6. View Traces
+
+Open your tracing backend UI:
+- Jaeger: http://localhost:16686
+- Select service: `order-service`
+- Click "Find Traces" to view the end-to-end traces
+
+## 🔧 AWS ADOT Lambda Layer
+
+This project uses the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation. The layer provides:
+
+### Key Benefits
+
+1. **Zero-Code Instrumentation** - Auto-instruments your Lambda function without code changes
+2. **No Dependency Bundling** - OpenTelemetry SDKs are provided by the layer, reducing deployment package size
+3. **Automatic Context Propagation** - Trace context is automatically propagated across service calls
+4. **AWS-Optimized** - Maintained and supported by AWS with regular updates
+
+### How It Works
+
+The layer works through the `AWS_LAMBDA_EXEC_WRAPPER` environment variable:
+
+```yaml
+Environment:
+  Variables:
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler  # Enables auto-instrumentation
+    OTEL_SERVICE_NAME: order-service              # Service identifier
+    OTEL_TRACES_SAMPLER: AlwaysOn                 # Sampling strategy
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+When your Lambda function is invoked:
+1. The wrapper initializes OpenTelemetry SDK
+2. Auto-instrumentation is activated for HTTP, AWS SDK, and Lambda runtime
+3. A root span is created for the Lambda invocation
+4. Your handler executes within the trace context
+5. Spans are exported to your configured OTLP endpoint
+
+### What Gets Instrumented Automatically
+
+- ✅ Lambda function invocations
+- ✅ HTTP/HTTPS requests (axios, node-fetch, native http/https)
+- ✅ AWS SDK v2 and v3 calls
+- ✅ Database clients (when using instrumented libraries)
+- ✅ Trace context propagation in headers
+
+### Adding Custom Instrumentation
+
+While the layer handles most instrumentation automatically, you can add custom spans for business logic:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service');
+  
+  return tracer.startActiveSpan('custom-operation', async (span) => {
+    span.setAttribute('business.attribute', 'value');
+    // Your logic here
+    span.end();
+  });
+};
+```
+
+For detailed configuration options, see [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md).
+
+## 📝 Test Scenarios
+
+### Scenario 1: Successful Order ✅
+
+Tests the happy path where all services succeed.
+
+```json
+{
+  "orderId": "ORD-001",
+  "customerId": "CUST-123",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-001",
+      "name": "Laptop",
+      "quantity": 1,
+      "price": 999.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Success)
+- Order completed with HTTP 200
+
+### Scenario 2: Out of Stock ⚠️
+
+Tests inventory unavailability.
+
+```json
+{
+  "orderId": "ORD-002",
+  "customerId": "CUST-456",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-003",
+      "name": "Keyboard",
+      "quantity": 1,
+      "price": 79.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Out of stock detected)
+- Payment Service NOT called
+- Order fails with HTTP 409
+
+**Out of Stock Items:**
+- `item-003` - Keyboard (0 in stock)
+- `item-005` - Headphones (0 in stock)
+
+### Scenario 3: Payment Failure 💳
+
+Tests payment processing failures.
+
+**Card Declined:**
+```json
+{
+  "orderId": "ORD-003",
+  "customerId": "CUST-789",
+  "paymentMethod": "4111111111111111",
+  "items": [{"itemId": "item-001", "quantity": 1, "price": 999.99}]
+}
+```
+
+**Insufficient Funds:**
+```json
+{
+  "orderId": "ORD-004",
+  "customerId": "CUST-999",
+  "paymentMethod": "4222222222222222",
+  "items": [{"itemId": "item-004", "quantity": 2, "price": 399.99}]
+}
+```
+
+**Test Payment Methods:**
+- `4111111111111111` - Card declined
+- `4222222222222222` - Insufficient funds
+- `4333333333333333` - Expired card
+- Any other value - Success (with 10% random failure rate)
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Payment fails)
+- Order fails with HTTP 402
+
+## 🔍 Understanding the Traces
+
+Each trace will show:
+
+1. **Span Attributes:**
+   - Order ID, Customer ID
+   - Item counts and details
+   - Payment amounts and methods
+   - Service names and versions
+   - Success/failure reasons
+
+2. **Span Hierarchy:**
+   ```
+   process-order (Order Service)
+   ├── check-inventory (Order Service -> Inventory Service)
+   │   └── check-inventory (Inventory Service)
+   └── process-payment (Order Service -> Payment Service)
+       └── process-payment (Payment Service)
+   ```
+
+3. **Trace Context Propagation:**
+   - Trace IDs are consistent across all services
+   - Parent-child relationships are maintained
+   - W3C traceparent headers are used
+
+## 🛠️ Configuration
+
+### Environment Variables
+
+Configure these in the SAM template or Lambda console:
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT` - OpenTelemetry Collector endpoint (default: `http://localhost:4318/v1/traces`)
+- `ENVIRONMENT` - Deployment environment (default: `development`)
+- `INVENTORY_SERVICE_URL` - Inventory service endpoint
+- `PAYMENT_SERVICE_URL` - Payment service endpoint
+
+### Inventory Configuration
+
+Modify the mock inventory in `src/inventory-service/index.js`:
+
+```javascript
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  // Add more items...
+};
+```
+
+### Payment Configuration
+
+Modify failure patterns in `src/payment-service/index.js`:
+
+```javascript
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  // Add more patterns...
+};
+```
+
+## 📂 Project Structure
+
+```
+lambda-opentelemetry-demo/
+├── src/
+│   ├── order-service/          # Order orchestration service
+│   │   └── index.js
+│   ├── inventory-service/      # Inventory check service
+│   │   └── index.js
+│   ├── payment-service/        # Payment processing service
+│   │   └── index.js
+│   └── shared/                 # Shared utilities
+│       ├── tracer.js           # OpenTelemetry setup
+│       └── utils.js            # Common utilities
+├── template.yaml               # AWS SAM template
+├── package.json                # Node.js dependencies
+├── test-payloads.json          # Sample test data
+├── test-api.sh                 # API test script
+└── README.md                   # This file
+```
+
+## 🔧 Local Development
+
+To test locally without deploying to AWS:
+
+1. Start your OpenTelemetry backend (e.g., Jaeger)
+2. Use AWS SAM Local:
+
+```bash
+sam build
+sam local start-api --env-vars env.json
+```
+
+Create `env.json`:
+```json
+{
+  "Parameters": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "INVENTORY_SERVICE_URL": "http://host.docker.internal:3000/inventory",
+    "PAYMENT_SERVICE_URL": "http://host.docker.internal:3000/payment"
+  }
+}
+```
+
+## 📊 Observability Best Practices
+
+This demo demonstrates several observability best practices:
+
+1. **Structured Logging** - Logs include trace context for correlation
+2. **Semantic Attributes** - Meaningful span attributes for filtering and analysis
+3. **Error Handling** - Errors are captured as span events
+4. **Business Context** - Business-relevant data in spans (order IDs, amounts, etc.)
+5. **Service Naming** - Clear service names for easy identification
+6. **Context Propagation** - W3C standard trace context across service boundaries
+
+## 🔐 Security Considerations
+
+- This is a demo project - do not use in production without proper security hardening
+- Implement proper authentication/authorization for API endpoints
+- Secure OpenTelemetry Collector endpoints
+- Use AWS Secrets Manager for sensitive configuration
+- Enable API Gateway throttling and request validation
+
+## 🤝 Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+## 📄 License
+
+MIT License - See LICENSE file for details
+
+## 🎓 Learning Resources
+
+- [OpenTelemetry Documentation](https://opentelemetry.io/docs/)
+- [AWS Lambda Best Practices](https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html)
+- [W3C Trace Context](https://www.w3.org/TR/trace-context/)
+- [Distributed Tracing Guide](https://opentelemetry.io/docs/concepts/signals/traces/)
+
+## 🐛 Troubleshooting
+
+### Traces not appearing in backend
+
+- Verify OTEL_EXPORTER_OTLP_ENDPOINT is correctly configured
+- Check Lambda logs in CloudWatch for errors
+- Ensure OpenTelemetry Collector/backend is running and accessible
+- Verify network connectivity between Lambda and collector
+
+### Service-to-service calls failing
+
+- Check that service URLs are correctly configured
+- Verify API Gateway endpoints are deployed
+- Review Lambda function logs for errors
+- Check IAM permissions if using private endpoints
+
+### High latency or timeouts
+
+- Increase Lambda timeout in template.yaml
+- Check OpenTelemetry Collector performance
+- Consider using asynchronous export
+- Review batch span processor configuration
diff --git a/.aws-sam/build/PaymentServiceFunction/docker-compose.yaml b/.aws-sam/build/PaymentServiceFunction/docker-compose.yaml
new file mode 100644
index 0000000..7f969f4
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/docker-compose.yaml
@@ -0,0 +1,37 @@
+version: '3.8'
+
+services:
+  # Jaeger all-in-one with OTLP support
+  jaeger:
+    image: jaegertracing/all-in-one:latest
+    container_name: jaeger-otel
+    environment:
+      - COLLECTOR_OTLP_ENABLED=true
+      - LOG_LEVEL=debug
+    ports:
+      - "16686:16686"  # Jaeger UI
+      - "4318:4318"    # OTLP HTTP receiver
+      - "4317:4317"    # OTLP gRPC receiver
+      - "14268:14268"  # Jaeger collector HTTP
+      - "14250:14250"  # Jaeger collector gRPC
+    networks:
+      - otel-demo
+
+  # Optional: OpenTelemetry Collector (if you want to use a separate collector)
+  # otel-collector:
+  #   image: otel/opentelemetry-collector-contrib:latest
+  #   container_name: otel-collector
+  #   command: ["--config=/etc/otel-collector-config.yaml"]
+  #   volumes:
+  #     - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+  #   ports:
+  #     - "4318:4318"    # OTLP HTTP receiver
+  #     - "4317:4317"    # OTLP gRPC receiver
+  #     - "8888:8888"    # Prometheus metrics
+  #     - "13133:13133"  # Health check
+  #   networks:
+  #     - otel-demo
+
+networks:
+  otel-demo:
+    driver: bridge
diff --git a/.aws-sam/build/PaymentServiceFunction/env.json b/.aws-sam/build/PaymentServiceFunction/env.json
new file mode 100644
index 0000000..67b70e4
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/env.json
@@ -0,0 +1,16 @@
+{
+  "OrderServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local",
+    "INVENTORY_SERVICE_URL": "http://127.0.0.1:3001/inventory",
+    "PAYMENT_SERVICE_URL": "http://127.0.0.1:3002/payment"
+  },
+  "InventoryServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  },
+  "PaymentServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  }
+}
diff --git a/.aws-sam/build/PaymentServiceFunction/local-test.sh b/.aws-sam/build/PaymentServiceFunction/local-test.sh
new file mode 100755
index 0000000..8b43c30
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/local-test.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Simple local testing script using SAM Local
+# This script starts SAM local API and runs tests
+
+set -e
+
+echo "Starting Lambda OpenTelemetry Demo Local Test"
+echo "=============================================="
+echo ""
+
+# Check if Docker is running
+if ! docker info > /dev/null 2>&1; then
+    echo "Error: Docker is not running. Please start Docker first."
+    exit 1
+fi
+
+# Check if Jaeger is running
+if ! docker ps | grep -q jaeger-otel; then
+    echo "Starting Jaeger..."
+    docker-compose up -d jaeger
+    echo "Waiting for Jaeger to be ready..."
+    sleep 5
+else
+    echo "Jaeger is already running"
+fi
+
+echo ""
+echo "Jaeger UI available at: http://localhost:16686"
+echo ""
+
+# Build the Lambda functions
+echo "Building Lambda functions..."
+sam build
+
+if [ $? -ne 0 ]; then
+    echo "Error: Build failed"
+    exit 1
+fi
+
+echo ""
+echo "Lambda functions built successfully!"
+echo ""
+echo "To test the API:"
+echo "1. Start SAM local API in one terminal:"
+echo "   sam local start-api --env-vars env.json"
+echo ""
+echo "2. In another terminal, run the test script:"
+echo "   ./test-api.sh http://127.0.0.1:3000"
+echo ""
+echo "3. View traces in Jaeger UI:"
+echo "   http://localhost:16686"
+echo ""
diff --git a/.aws-sam/build/PaymentServiceFunction/package-lock.json b/.aws-sam/build/PaymentServiceFunction/package-lock.json
new file mode 100644
index 0000000..eeb2106
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/package-lock.json
@@ -0,0 +1,295 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "lambda-opentelemetry-demo",
+      "version": "1.0.0",
+      "license": "MIT",
+      "dependencies": {
+        "axios": "^1.13.5"
+      }
+    },
+    "node_modules/asynckit": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
+      "license": "MIT"
+    },
+    "node_modules/axios": {
+      "version": "1.13.5",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.13.5.tgz",
+      "integrity": "sha512-cz4ur7Vb0xS4/KUN0tPWe44eqxrIu31me+fbang3ijiNscE129POzipJJA6zniq2C/Z6sJCjMimjS8Lc/GAs8Q==",
+      "license": "MIT",
+      "dependencies": {
+        "follow-redirects": "^1.15.11",
+        "form-data": "^4.0.5",
+        "proxy-from-env": "^1.1.0"
+      }
+    },
+    "node_modules/call-bind-apply-helpers": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
+      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/combined-stream": {
+      "version": "1.0.8",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "license": "MIT",
+      "dependencies": {
+        "delayed-stream": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
+    "node_modules/delayed-stream": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
+      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
+    "node_modules/dunder-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
+      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "gopd": "^1.2.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-define-property": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
+      "integrity": "sha512-e3nRfgfUZ4rNGL232gUgX06QNyyez04KdjFrF+LTRoOXmrOgFKDg4BCdsjW8EnT69eqdYGmRpJwiPVYNrCaW3g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-errors": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
+      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-object-atoms": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.1.tgz",
+      "integrity": "sha512-FGgH2h8zKNim9ljj7dankFPcICIK9Cp5bm+c2gQSYePhpaG5+esrLODihIorn+Pe6FGJzWhXQotPv73jTaldXA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-set-tostringtag": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/es-set-tostringtag/-/es-set-tostringtag-2.1.0.tgz",
+      "integrity": "sha512-j6vWzfrGVfyXxge+O0x5sh6cvxAog0a/4Rdd2K36zCMV5eJ+/+tOAngRO8cODMNWbVRdVlmGZQL2YS3yR8bIUA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "get-intrinsic": "^1.2.6",
+        "has-tostringtag": "^1.0.2",
+        "hasown": "^2.0.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/follow-redirects": {
+      "version": "1.15.11",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.11.tgz",
+      "integrity": "sha512-deG2P0JfjrTxl50XGCDyfI97ZGVCxIpfKYmfyrQ54n5FO/0gfIES8C/Psl6kWVDolizcaaxZJnTS0QSMxvnsBQ==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/form-data": {
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.5.tgz",
+      "integrity": "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==",
+      "license": "MIT",
+      "dependencies": {
+        "asynckit": "^0.4.0",
+        "combined-stream": "^1.0.8",
+        "es-set-tostringtag": "^2.1.0",
+        "hasown": "^2.0.2",
+        "mime-types": "^2.1.12"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/function-bind": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
+      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-intrinsic": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
+      "integrity": "sha512-9fSjSaos/fRIVIp+xSJlE6lfwhES7LNtKaCBIamHsjr2na1BiABJPo0mOjjz8GJDURarmCPGqaiVg5mfjb98CQ==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.2",
+        "es-define-property": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "es-object-atoms": "^1.1.1",
+        "function-bind": "^1.1.2",
+        "get-proto": "^1.0.1",
+        "gopd": "^1.2.0",
+        "has-symbols": "^1.1.0",
+        "hasown": "^2.0.2",
+        "math-intrinsics": "^1.1.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
+      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
+      "license": "MIT",
+      "dependencies": {
+        "dunder-proto": "^1.0.1",
+        "es-object-atoms": "^1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/gopd": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
+      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-symbols": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.1.0.tgz",
+      "integrity": "sha512-1cDNdwJ2Jaohmb3sg4OmKaMBwuC48sYni5HUw2DvsC8LjGTLK9h+eb1X6RyuOHe4hT0ULCW68iomhjUoKUqlPQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-tostringtag": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/has-tostringtag/-/has-tostringtag-1.0.2.tgz",
+      "integrity": "sha512-NqADB8VjPFLM2V0VvHUewwwsw0ZWBaIdgo+ieHtK3hasLz4qeCRjYcqfB6AQrBggRKppKF8L52/VqdVsO47Dlw==",
+      "license": "MIT",
+      "dependencies": {
+        "has-symbols": "^1.0.3"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/hasown": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.2.tgz",
+      "integrity": "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/math-intrinsics": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
+      "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/mime-db": {
+      "version": "1.52.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
+      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/mime-types": {
+      "version": "2.1.35",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
+      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/proxy-from-env": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
+      "integrity": "sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==",
+      "license": "MIT"
+    }
+  }
+}
diff --git a/.aws-sam/build/PaymentServiceFunction/package.json b/.aws-sam/build/PaymentServiceFunction/package.json
new file mode 100644
index 0000000..abe61a7
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/package.json
@@ -0,0 +1,23 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "description": "Sample AWS Lambda project demonstrating OpenTelemetry integration without CloudWatch/X-Ray",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"No tests specified\" && exit 0",
+    "deploy": "sam deploy --guided",
+    "build": "sam build"
+  },
+  "keywords": [
+    "aws",
+    "lambda",
+    "opentelemetry",
+    "tracing",
+    "nodejs"
+  ],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "axios": "^1.13.5"
+  }
+}
diff --git a/.aws-sam/build/PaymentServiceFunction/src/inventory-service/index.js b/.aws-sam/build/PaymentServiceFunction/src/inventory-service/index.js
new file mode 100644
index 0000000..7cb0b00
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/src/inventory-service/index.js
@@ -0,0 +1,143 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock inventory database
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  'item-004': { name: 'Monitor', quantity: 5 },
+  'item-005': { name: 'Headphones', quantity: 0 }, // Out of stock
+};
+
+/**
+ * Inventory Service Lambda Handler
+ * This service checks if requested items are available in inventory
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Inventory Service received event:', JSON.stringify(event));
+
+  return withSpan('check-inventory', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, items } = body;
+
+      // Validate input
+      if (!orderId || !items || !Array.isArray(items)) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing or invalid required fields',
+        });
+        return createResponse(400, {
+          available: false,
+          error: 'Missing or invalid required fields: orderId, items (array)',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'inventory.items.count': items.length,
+      });
+
+      console.log(`Checking inventory for order ${orderId}`);
+
+      // Check each item
+      const unavailableItems = [];
+      let allAvailable = true;
+
+      for (const item of items) {
+        const { itemId, quantity } = item;
+        
+        if (!itemId || !quantity) {
+          continue;
+        }
+
+        addSpanAttributes({
+          [`inventory.item.${itemId}.requested`]: quantity,
+        });
+
+        // Check if item exists in inventory
+        if (!inventory[itemId]) {
+          console.log(`Item ${itemId} not found in inventory`);
+          unavailableItems.push({
+            itemId,
+            reason: 'Item not found',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'not-found',
+          });
+          continue;
+        }
+
+        const availableQuantity = inventory[itemId].quantity;
+        addSpanAttributes({
+          [`inventory.item.${itemId}.available`]: availableQuantity,
+        });
+
+        // Check if sufficient quantity is available
+        if (availableQuantity < quantity) {
+          console.log(`Insufficient quantity for item ${itemId}. Requested: ${quantity}, Available: ${availableQuantity}`);
+          unavailableItems.push({
+            itemId,
+            name: inventory[itemId].name,
+            requestedQuantity: quantity,
+            availableQuantity: availableQuantity,
+            reason: availableQuantity === 0 ? 'Out of stock' : 'Insufficient quantity',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'insufficient',
+          });
+        } else {
+          console.log(`Item ${itemId} is available. Requested: ${quantity}, Available: ${availableQuantity}`);
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'available',
+          });
+        }
+      }
+
+      addSpanAttributes({
+        'inventory.all_available': allAvailable,
+        'inventory.unavailable_count': unavailableItems.length,
+      });
+
+      if (allAvailable) {
+        console.log(`All items available for order ${orderId}`);
+        
+        return createResponse(200, {
+          available: true,
+          orderId,
+          message: 'All items are available',
+        });
+      } else {
+        console.log(`Some items unavailable for order ${orderId}:`, unavailableItems);
+        addSpanAttributes({
+          'inventory.failure_reason': 'items-unavailable',
+        });
+        
+        return createResponse(200, {
+          available: false,
+          orderId,
+          unavailableItems,
+          message: 'Some items are not available',
+        });
+      }
+
+    } catch (error) {
+      console.error('Inventory check error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        available: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/PaymentServiceFunction/src/order-service/index.js b/.aws-sam/build/PaymentServiceFunction/src/order-service/index.js
new file mode 100644
index 0000000..7d05578
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/src/order-service/index.js
@@ -0,0 +1,181 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { callService, createResponse } = require('../shared/utils');
+
+/**
+ * Order Service Lambda Handler
+ * This service accepts orders and orchestrates calls to Inventory and Payment services
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Order Service received event:', JSON.stringify(event));
+
+  return withSpan('process-order', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, items, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !items || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, items, paymentMethod',
+        });
+      }
+
+      // Add order details to span
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'order.items.count': items.length,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing order ${orderId} for customer ${customerId}`);
+
+      // Step 1: Check inventory
+      console.log('Step 1: Checking inventory');
+      const inventoryUrl = process.env.INVENTORY_SERVICE_URL || 'http://localhost:3001/inventory';
+      
+      let inventoryResult;
+      try {
+        inventoryResult = await withSpan('check-inventory', async (inventorySpan) => {
+          addSpanAttributes({
+            'service': 'inventory',
+            'order.id': orderId,
+          });
+          
+          const result = await callService(inventoryUrl, {
+            orderId,
+            items,
+          });
+          
+          addSpanAttributes({
+            'inventory.available': result.available,
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Inventory check failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Inventory check failed',
+          details: error.message,
+        });
+      }
+
+      if (!inventoryResult.available) {
+        addSpanAttributes({
+          'inventory.status': 'out-of-stock',
+          'inventory.unavailable_items': JSON.stringify(inventoryResult.unavailableItems || []),
+        });
+        
+        console.log(`Order ${orderId} failed: Items out of stock`);
+        return createResponse(409, {
+          success: false,
+          orderId,
+          error: 'Items out of stock',
+          unavailableItems: inventoryResult.unavailableItems,
+        });
+      }
+
+      addSpanAttributes({ 'inventory.status': 'available' });
+
+      // Step 2: Process payment
+      console.log('Step 2: Processing payment');
+      const paymentUrl = process.env.PAYMENT_SERVICE_URL || 'http://localhost:3002/payment';
+      
+      let paymentResult;
+      try {
+        paymentResult = await withSpan('process-payment', async (paymentSpan) => {
+          const totalAmount = items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
+          
+          addSpanAttributes({
+            'service': 'payment',
+            'order.id': orderId,
+            'payment.method': paymentMethod,
+            'payment.amount': totalAmount,
+          });
+          
+          const result = await callService(paymentUrl, {
+            orderId,
+            customerId,
+            amount: totalAmount,
+            paymentMethod,
+          });
+          
+          addSpanAttributes({
+            'payment.success': result.success,
+            'payment.transaction_id': result.transactionId || 'none',
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Payment processing failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Payment processing failed',
+          details: error.message,
+        });
+      }
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.status': 'failed',
+          'payment.failure_reason': paymentResult.reason || 'unknown',
+        });
+        
+        console.log(`Order ${orderId} failed: Payment failed`);
+        return createResponse(402, {
+          success: false,
+          orderId,
+          error: 'Payment failed',
+          reason: paymentResult.reason,
+        });
+      }
+
+      addSpanAttributes({
+        'payment.status': 'success',
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      // Order successful
+      console.log(`Order ${orderId} completed successfully`);
+      
+      return createResponse(200, {
+        success: true,
+        orderId,
+        message: 'Order processed successfully',
+        transactionId: paymentResult.transactionId,
+        totalAmount: items.reduce((sum, item) => sum + (item.price * item.quantity), 0),
+      });
+
+    } catch (error) {
+      console.error('Order processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/PaymentServiceFunction/src/payment-service/index.js b/.aws-sam/build/PaymentServiceFunction/src/payment-service/index.js
new file mode 100644
index 0000000..6a88ea6
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/src/payment-service/index.js
@@ -0,0 +1,144 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock payment processing
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  'expired-card': ['4333333333333333', 'expired-card'],
+};
+
+/**
+ * Simulate payment processing with some failure scenarios
+ * @param {string} paymentMethod - Payment method identifier
+ * @param {number} amount - Payment amount
+ * @returns {Object} Payment result
+ */
+function processPayment(paymentMethod, amount) {
+  // Check for known failure patterns
+  for (const [reason, patterns] of Object.entries(FAILURE_PATTERNS)) {
+    if (patterns.some(pattern => paymentMethod.includes(pattern))) {
+      return {
+        success: false,
+        reason: reason.replace('-', ' '),
+        transactionId: null,
+      };
+    }
+  }
+
+  // Simulate random failures (10% chance)
+  if (Math.random() < 0.1) {
+    const reasons = ['network-timeout', 'gateway-error', 'rate-limit-exceeded'];
+    const randomReason = reasons[Math.floor(Math.random() * reasons.length)];
+    return {
+      success: false,
+      reason: randomReason.replace('-', ' '),
+      transactionId: null,
+    };
+  }
+
+  // Successful payment
+  return {
+    success: true,
+    transactionId: `txn-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`,
+  };
+}
+
+/**
+ * Payment Service Lambda Handler
+ * This service processes payments with failure scenarios for testing
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Payment Service received event:', JSON.stringify(event));
+
+  return withSpan('process-payment', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, amount, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !amount || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, amount, paymentMethod',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'payment.amount': amount,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing payment for order ${orderId}, amount: ${amount}`);
+
+      // Validate amount
+      if (amount <= 0) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Invalid payment amount',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Invalid payment amount',
+        });
+      }
+
+      // Process payment
+      const paymentResult = processPayment(paymentMethod, amount);
+
+      addSpanAttributes({
+        'payment.success': paymentResult.success,
+      });
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.failure_reason': paymentResult.reason,
+        });
+        
+        console.log(`Payment failed for order ${orderId}: ${paymentResult.reason}`);
+        
+        return createResponse(200, {
+          success: false,
+          orderId,
+          reason: paymentResult.reason,
+          message: 'Payment processing failed',
+        });
+      }
+
+      addSpanAttributes({
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      console.log(`Payment successful for order ${orderId}. Transaction ID: ${paymentResult.transactionId}`);
+
+      return createResponse(200, {
+        success: true,
+        orderId,
+        transactionId: paymentResult.transactionId,
+        amount,
+        message: 'Payment processed successfully',
+      });
+
+    } catch (error) {
+      console.error('Payment processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/.aws-sam/build/PaymentServiceFunction/src/shared/tracer.js b/.aws-sam/build/PaymentServiceFunction/src/shared/tracer.js
new file mode 100644
index 0000000..3cedef5
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/src/shared/tracer.js
@@ -0,0 +1,118 @@
+// When using OpenTelemetry Lambda Layer with auto-instrumentation,
+// the @opentelemetry/api is provided by the layer at /opt/nodejs/node_modules
+const api = require('@opentelemetry/api');
+
+/**
+ * Get the current active span
+ * The Lambda Layer automatically creates spans for Lambda invocations
+ * @returns {Span} Current active span
+ */
+function getCurrentSpan() {
+  return api.trace.getActiveSpan();
+}
+
+/**
+ * Get a tracer instance
+ * @param {string} name - Tracer name (usually service name)
+ * @param {string} version - Service version
+ * @returns {Tracer} OpenTelemetry tracer instance
+ */
+function getTracer(name = 'lambda-app', version = '1.0.0') {
+  return api.trace.getTracer(name, version);
+}
+
+/**
+ * Create a new span for a specific operation
+ * @param {string} spanName - Name of the span
+ * @param {Function} fn - Function to execute within the span
+ * @param {Object} attributes - Optional span attributes
+ * @returns {Promise} Result of the function execution
+ */
+async function withSpan(spanName, fn, attributes = {}) {
+  const tracer = getTracer();
+  return tracer.startActiveSpan(spanName, async (span) => {
+    try {
+      // Add custom attributes
+      Object.entries(attributes).forEach(([key, value]) => {
+        span.setAttribute(key, value);
+      });
+      
+      const result = await fn(span);
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.setStatus({
+        code: api.SpanStatusCode.ERROR,
+        message: error.message,
+      });
+      span.recordException(error);
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+}
+
+/**
+ * Add custom attributes to the current span
+ * @param {Object} attributes - Key-value pairs of attributes to add
+ */
+function addSpanAttributes(attributes) {
+  const span = getCurrentSpan();
+  if (span) {
+    Object.entries(attributes).forEach(([key, value]) => {
+      if (value !== null && value !== undefined) {
+        span.setAttribute(key, value);
+      }
+    });
+  }
+}
+
+/**
+ * Record an exception on the current span
+ * @param {Error} error - Error to record
+ */
+function recordException(error) {
+  const span = getCurrentSpan();
+  if (span) {
+    span.recordException(error);
+    span.setStatus({
+      code: api.SpanStatusCode.ERROR,
+      message: error.message,
+    });
+  }
+}
+
+/**
+ * Inject trace context into headers for downstream service calls
+ * Uses W3C Trace Context propagation
+ * @returns {Object} Headers with trace context
+ */
+function injectTraceContext() {
+  const headers = {};
+  const span = getCurrentSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    if (spanContext && spanContext.traceId && spanContext.spanId) {
+      // W3C Trace Context format
+      const traceFlags = spanContext.traceFlags || 0;
+      headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-${traceFlags.toString(16).padStart(2, '0')}`;
+      
+      if (spanContext.traceState) {
+        headers.tracestate = spanContext.traceState.serialize();
+      }
+    }
+  }
+  
+  return headers;
+}
+
+module.exports = {
+  getTracer,
+  getCurrentSpan,
+  withSpan,
+  addSpanAttributes,
+  recordException,
+  injectTraceContext,
+};
diff --git a/.aws-sam/build/PaymentServiceFunction/src/shared/utils.js b/.aws-sam/build/PaymentServiceFunction/src/shared/utils.js
new file mode 100644
index 0000000..2da73e3
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/src/shared/utils.js
@@ -0,0 +1,61 @@
+const axios = require('axios');
+const { injectTraceContext } = require('./tracer');
+
+/**
+ * Make an HTTP request to another Lambda service with trace context propagation
+ * @param {string} url - Service URL
+ * @param {Object} data - Request payload
+ * @param {string} method - HTTP method (default: POST)
+ * @returns {Promise<Object>} Response data
+ */
+async function callService(url, data, method = 'POST') {
+  // Inject trace context into headers
+  const headers = {
+    'Content-Type': 'application/json',
+    ...injectTraceContext(),
+  };
+
+  console.log(`Calling service: ${url} with method: ${method}`);
+  console.log(`Trace context headers:`, headers);
+
+  try {
+    const response = await axios({
+      method,
+      url,
+      data,
+      headers,
+    });
+
+    console.log(`Service call successful: ${url}`);
+    return response.data;
+  } catch (error) {
+    console.error(`Service call failed: ${url}`, error.message);
+    if (error.response) {
+      throw new Error(`Service call failed: ${error.response.status} - ${JSON.stringify(error.response.data)}`);
+    }
+    throw error;
+  }
+}
+
+/**
+ * Create a Lambda response object
+ * @param {number} statusCode - HTTP status code
+ * @param {Object} body - Response body
+ * @param {Object} headers - Additional headers
+ * @returns {Object} Lambda response object
+ */
+function createResponse(statusCode, body, headers = {}) {
+  return {
+    statusCode,
+    headers: {
+      'Content-Type': 'application/json',
+      ...headers,
+    },
+    body: JSON.stringify(body),
+  };
+}
+
+module.exports = {
+  callService,
+  createResponse,
+};
diff --git a/.aws-sam/build/PaymentServiceFunction/template.yaml b/.aws-sam/build/PaymentServiceFunction/template.yaml
new file mode 100644
index 0000000..bc11944
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/template.yaml
@@ -0,0 +1,137 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: Lambda OpenTelemetry Demo - Order, Inventory, and Payment Services with AWS ADOT Layer
+
+Globals:
+  Function:
+    Timeout: 30
+    MemorySize: 512
+    Runtime: nodejs20.x
+    Environment:
+      Variables:
+        AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+        OTEL_SERVICE_NAME: will-be-overridden
+        OTEL_TRACES_SAMPLER: AlwaysOn
+        OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+        OTEL_EXPORTER_OTLP_ENDPOINT: !Ref OtelCollectorEndpoint
+        OTEL_PROPAGATORS: tracecontext
+        OTEL_RESOURCE_ATTRIBUTES: !Sub deployment.environment=${Environment}
+
+Parameters:
+  OtelCollectorEndpoint:
+    Type: String
+    Default: 'http://localhost:4318'
+    Description: OpenTelemetry Collector endpoint URL (without /v1/traces path)
+  
+  Environment:
+    Type: String
+    Default: 'production'
+    Description: Deployment environment (e.g., development, staging, production)
+  
+  AdotLayerArn:
+    Type: String
+    Default: 'arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5'
+    Description: |
+      ARN of the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for Node.js.
+      Find the latest ARN for your region at:
+      https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Resources:
+  # Order Service Function
+  OrderServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: order-service
+      CodeUri: ./
+      Handler: src/order-service/index.handler
+      Description: Order Service - Orchestrates order processing
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: order-service
+          INVENTORY_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+          PAYMENT_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+      Events:
+        OrderApi:
+          Type: Api
+          Properties:
+            Path: /order
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Inventory Service Function
+  InventoryServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: inventory-service
+      CodeUri: ./
+      Handler: src/inventory-service/index.handler
+      Description: Inventory Service - Checks item availability
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: inventory-service
+      Events:
+        InventoryApi:
+          Type: Api
+          Properties:
+            Path: /inventory
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Payment Service Function
+  PaymentServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: payment-service
+      CodeUri: ./
+      Handler: src/payment-service/index.handler
+      Description: Payment Service - Processes payments
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: payment-service
+      Events:
+        PaymentApi:
+          Type: Api
+          Properties:
+            Path: /payment
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # API Gateway
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+      Description: API Gateway for Lambda OpenTelemetry Demo
+
+Outputs:
+  ApiEndpoint:
+    Description: API Gateway endpoint URL
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod'
+  
+  OrderServiceUrl:
+    Description: Order Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/order'
+    
+  InventoryServiceUrl:
+    Description: Inventory Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+    
+  PaymentServiceUrl:
+    Description: Payment Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+  
+  AdotLayerVersion:
+    Description: ADOT Lambda Layer ARN being used
+    Value: !Ref AdotLayerArn
diff --git a/.aws-sam/build/PaymentServiceFunction/test-api.sh b/.aws-sam/build/PaymentServiceFunction/test-api.sh
new file mode 100755
index 0000000..680b864
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/test-api.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+
+# Color codes for output
+GREEN='\033[0;32m'
+BLUE='\033[0;34m'
+YELLOW='\033[1;33m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+echo -e "${BLUE}========================================${NC}"
+echo -e "${BLUE}Lambda OpenTelemetry Demo - Test Script${NC}"
+echo -e "${BLUE}========================================${NC}"
+echo ""
+
+# Check if API endpoint is provided
+if [ -z "$1" ]; then
+    echo -e "${RED}Error: API endpoint is required${NC}"
+    echo "Usage: ./test-api.sh <API_ENDPOINT>"
+    echo "Example: ./test-api.sh https://abc123.execute-api.us-east-1.amazonaws.com/Prod"
+    exit 1
+fi
+
+API_ENDPOINT=$1
+ORDER_URL="${API_ENDPOINT}/order"
+
+echo -e "${YELLOW}Using API Endpoint: ${API_ENDPOINT}${NC}"
+echo ""
+
+# Test 1: Successful Order
+echo -e "${BLUE}Test 1: Successful Order${NC}"
+echo "Testing with items that are in stock and valid payment method..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 2: Out of Stock Order
+echo -e "${BLUE}Test 2: Out of Stock Order${NC}"
+echo "Testing with items that are out of stock..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 3: Payment Failure (Card Declined)
+echo -e "${BLUE}Test 3: Payment Failure - Card Declined${NC}"
+echo "Testing with a payment method that will be declined..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 4: Payment Failure (Insufficient Funds)
+echo -e "${BLUE}Test 4: Payment Failure - Insufficient Funds${NC}"
+echo "Testing with insufficient funds scenario..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+echo -e "${GREEN}========================================${NC}"
+echo -e "${GREEN}All tests completed!${NC}"
+echo -e "${GREEN}Check your OpenTelemetry backend to view the traces${NC}"
+echo -e "${GREEN}========================================${NC}"
diff --git a/.aws-sam/build/PaymentServiceFunction/test-payloads.json b/.aws-sam/build/PaymentServiceFunction/test-payloads.json
new file mode 100644
index 0000000..603d30c
--- /dev/null
+++ b/.aws-sam/build/PaymentServiceFunction/test-payloads.json
@@ -0,0 +1,66 @@
+{
+  "successfulOrder": {
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  },
+  "outOfStockOrder": {
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  },
+  "paymentFailureOrder": {
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  },
+  "insufficientFundsOrder": {
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }
+}
diff --git a/.aws-sam/build/template.yaml b/.aws-sam/build/template.yaml
new file mode 100644
index 0000000..a8e7e8c
--- /dev/null
+++ b/.aws-sam/build/template.yaml
@@ -0,0 +1,140 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: Lambda OpenTelemetry Demo - Order, Inventory, and Payment Services with
+  AWS ADOT Layer
+Globals:
+  Function:
+    Timeout: 30
+    MemorySize: 512
+    Runtime: nodejs20.x
+    Environment:
+      Variables:
+        AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+        OTEL_SERVICE_NAME: will-be-overridden
+        OTEL_TRACES_SAMPLER: AlwaysOn
+        OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+        OTEL_EXPORTER_OTLP_ENDPOINT:
+          Ref: OtelCollectorEndpoint
+        OTEL_PROPAGATORS: tracecontext
+        OTEL_RESOURCE_ATTRIBUTES:
+          Fn::Sub: deployment.environment=${Environment}
+Parameters:
+  OtelCollectorEndpoint:
+    Type: String
+    Default: http://localhost:4318
+    Description: OpenTelemetry Collector endpoint URL (without /v1/traces path)
+  Environment:
+    Type: String
+    Default: production
+    Description: Deployment environment (e.g., development, staging, production)
+  AdotLayerArn:
+    Type: String
+    Default: arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5
+    Description: 'ARN of the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for
+      Node.js.
+
+      Find the latest ARN for your region at:
+
+      https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+      '
+Resources:
+  OrderServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+      SamResourceId: OrderServiceFunction
+    Properties:
+      FunctionName: order-service
+      CodeUri: OrderServiceFunction
+      Handler: src/order-service/index.handler
+      Description: Order Service - Orchestrates order processing
+      Layers:
+      - Ref: AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: order-service
+          INVENTORY_SERVICE_URL:
+            Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory
+          PAYMENT_SERVICE_URL:
+            Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment
+      Events:
+        OrderApi:
+          Type: Api
+          Properties:
+            Path: /order
+            Method: post
+            RestApiId:
+              Ref: ApiGateway
+  InventoryServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+      SamResourceId: InventoryServiceFunction
+    Properties:
+      FunctionName: inventory-service
+      CodeUri: InventoryServiceFunction
+      Handler: src/inventory-service/index.handler
+      Description: Inventory Service - Checks item availability
+      Layers:
+      - Ref: AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: inventory-service
+      Events:
+        InventoryApi:
+          Type: Api
+          Properties:
+            Path: /inventory
+            Method: post
+            RestApiId:
+              Ref: ApiGateway
+  PaymentServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+      SamResourceId: PaymentServiceFunction
+    Properties:
+      FunctionName: payment-service
+      CodeUri: PaymentServiceFunction
+      Handler: src/payment-service/index.handler
+      Description: Payment Service - Processes payments
+      Layers:
+      - Ref: AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: payment-service
+      Events:
+        PaymentApi:
+          Type: Api
+          Properties:
+            Path: /payment
+            Method: post
+            RestApiId:
+              Ref: ApiGateway
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+      Description: API Gateway for Lambda OpenTelemetry Demo
+Outputs:
+  ApiEndpoint:
+    Description: API Gateway endpoint URL
+    Value:
+      Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod
+  OrderServiceUrl:
+    Description: Order Service endpoint
+    Value:
+      Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/order
+  InventoryServiceUrl:
+    Description: Inventory Service endpoint
+    Value:
+      Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory
+  PaymentServiceUrl:
+    Description: Payment Service endpoint
+    Value:
+      Fn::Sub: https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment
+  AdotLayerVersion:
+    Description: ADOT Lambda Layer ARN being used
+    Value:
+      Ref: AdotLayerArn
diff --git a/.env.example b/.env.example
new file mode 100644
index 0000000..3f3aa74
--- /dev/null
+++ b/.env.example
@@ -0,0 +1,7 @@
+# OpenTelemetry Configuration
+OTEL_EXPORTER_OTLP_ENDPOINT=http://localhost:4318/v1/traces
+ENVIRONMENT=development
+
+# Service URLs (for local testing)
+INVENTORY_SERVICE_URL=http://localhost:3001/inventory
+PAYMENT_SERVICE_URL=http://localhost:3002/payment
diff --git a/ADOT-LAYER-CONFIG.md b/ADOT-LAYER-CONFIG.md
new file mode 100644
index 0000000..cffddc9
--- /dev/null
+++ b/ADOT-LAYER-CONFIG.md
@@ -0,0 +1,366 @@
+# AWS ADOT Lambda Layer Configuration Guide
+
+This document explains how to configure and use the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for automatic instrumentation.
+
+## Overview
+
+The AWS ADOT Lambda Layer provides automatic OpenTelemetry instrumentation for Lambda functions without requiring you to bundle OpenTelemetry SDKs in your deployment package.
+
+## Layer ARNs by Region
+
+### Node.js 18.x ADOT Layer ARNs (Latest: v1-18-1)
+
+| Region | ARN |
+|--------|-----|
+| us-east-1 | `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-east-2 | `arn:aws:lambda:us-east-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-1 | `arn:aws:lambda:us-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| us-west-2 | `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-west-1 | `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| eu-central-1 | `arn:aws:lambda:eu-central-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-southeast-1 | `arn:aws:lambda:ap-southeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+| ap-northeast-1 | `arn:aws:lambda:ap-northeast-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5` |
+
+**Find the latest ARNs**: https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+## Required Environment Variables
+
+### Essential Configuration
+
+```yaml
+Environment:
+  Variables:
+    # Enable ADOT auto-instrumentation wrapper
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+    
+    # Service name for identification in traces
+    OTEL_SERVICE_NAME: your-service-name
+    
+    # Sampling configuration (AlwaysOn for demo, adjust for production)
+    OTEL_TRACES_SAMPLER: AlwaysOn
+    
+    # Protocol for OTLP export
+    OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+    
+    # OpenTelemetry Collector endpoint (without /v1/traces)
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://your-collector:4318
+    
+    # Trace context propagation format
+    OTEL_PROPAGATORS: tracecontext
+```
+
+### Advanced Configuration Options
+
+```yaml
+Environment:
+  Variables:
+    # Resource attributes (for environment, version, etc.)
+    OTEL_RESOURCE_ATTRIBUTES: deployment.environment=production,service.version=1.0.0
+    
+    # Specific endpoint for traces (optional, overrides OTEL_EXPORTER_OTLP_ENDPOINT)
+    OTEL_EXPORTER_OTLP_TRACES_ENDPOINT: http://your-collector:4318/v1/traces
+    
+    # Enable/disable specific instrumentations
+    OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: true
+    OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+    
+    # Span attribute limits
+    OTEL_SPAN_ATTRIBUTE_VALUE_LENGTH_LIMIT: 4095
+    OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 128
+```
+
+## Exporter Backends
+
+### 1. Jaeger (Local Development)
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://localhost:4318
+OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+```
+
+Run Jaeger with OTLP support:
+```bash
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+```
+
+### 2. AWS X-Ray (with ADOT Collector)
+
+If you want to send traces to AWS X-Ray, deploy an ADOT Collector in your VPC:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://adot-collector:4318
+OTEL_PROPAGATORS: tracecontext,xray
+```
+
+ADOT Collector configuration:
+```yaml
+receivers:
+  otlp:
+    protocols:
+      http:
+        endpoint: 0.0.0.0:4318
+
+exporters:
+  awsxray:
+    region: us-east-1
+
+service:
+  pipelines:
+    traces:
+      receivers: [otlp]
+      exporters: [awsxray]
+```
+
+### 3. Grafana Cloud / Honeycomb / DataDog
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: https://your-saas-endpoint
+OTEL_EXPORTER_OTLP_HEADERS: Authorization=Bearer your-api-key
+```
+
+### 4. Self-Hosted OpenTelemetry Collector
+
+Deploy a collector in your VPC or use Lambda Extension:
+
+```yaml
+OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+## How Auto-Instrumentation Works
+
+### 1. Wrapper Execution
+
+The `AWS_LAMBDA_EXEC_WRAPPER` environment variable points to `/opt/otel-handler`, which:
+- Initializes the OpenTelemetry SDK before your handler
+- Automatically instruments common libraries (http, https, aws-sdk, etc.)
+- Creates a root span for each Lambda invocation
+- Propagates trace context from incoming requests
+
+### 2. Automatic Instrumentation
+
+The layer automatically instruments:
+- ✅ AWS SDK calls
+- ✅ HTTP/HTTPS requests (axios, node-fetch, http, https)
+- ✅ Lambda invocation (creates root span)
+- ✅ Downstream service calls with trace context propagation
+
+### 3. Context Propagation
+
+The layer automatically:
+- Extracts W3C trace context from incoming API Gateway requests
+- Injects trace context into outgoing HTTP requests
+- Maintains trace context across async operations
+
+## Usage in Your Code
+
+### Basic Usage (Automatic)
+
+With the layer configured, your Lambda function is automatically instrumented:
+
+```javascript
+exports.handler = async (event) => {
+  // Automatically traced!
+  const response = await axios.get('https://api.example.com');
+  return { statusCode: 200, body: JSON.stringify(response.data) };
+};
+```
+
+### Adding Custom Spans
+
+For additional business logic spans:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service', '1.0.0');
+  
+  return tracer.startActiveSpan('business-operation', async (span) => {
+    try {
+      span.setAttribute('customer.id', event.customerId);
+      
+      // Your business logic
+      const result = await processOrder(event);
+      
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.recordException(error);
+      span.setStatus({ code: api.SpanStatusCode.ERROR });
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+};
+```
+
+### Adding Attributes to Current Span
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const span = api.trace.getActiveSpan();
+  if (span) {
+    span.setAttribute('order.id', event.orderId);
+    span.setAttribute('order.amount', event.amount);
+  }
+  
+  // Your handler logic
+};
+```
+
+## Trace Context Propagation
+
+### Automatic (HTTP Clients)
+
+The layer automatically propagates context for instrumented HTTP clients:
+
+```javascript
+const axios = require('axios');
+
+// Trace context is automatically added to headers!
+const response = await axios.post('https://api.example.com/payment', data);
+```
+
+### Manual (Custom Clients)
+
+For custom HTTP clients or non-instrumented libraries:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+function getTraceHeaders() {
+  const headers = {};
+  const span = api.trace.getActiveSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-01`;
+  }
+  
+  return headers;
+}
+
+// Use in your custom client
+const headers = { ...getTraceHeaders(), 'Content-Type': 'application/json' };
+```
+
+## Sampling
+
+### AlwaysOn (Development/Demo)
+
+```yaml
+OTEL_TRACES_SAMPLER: AlwaysOn
+```
+
+Traces every request. Good for development but expensive in production.
+
+### TraceIdRatioBased (Production)
+
+```yaml
+OTEL_TRACES_SAMPLER: TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1  # 10% sampling
+```
+
+Samples a percentage of requests to reduce costs.
+
+### ParentBased (Recommended)
+
+```yaml
+OTEL_TRACES_SAMPLER: ParentBased_TraceIdRatioBased
+OTEL_TRACES_SAMPLER_ARG: 0.1
+```
+
+Respects parent sampling decisions while applying ratio-based sampling to root spans.
+
+## Performance Considerations
+
+### Cold Start Impact
+
+The ADOT layer adds ~200-300ms to cold start time:
+- Layer initialization: ~100ms
+- Auto-instrumentation setup: ~100-200ms
+
+### Runtime Overhead
+
+- Minimal overhead during warm execution (<5ms per invocation)
+- Async span export doesn't block Lambda execution
+- Batching reduces network calls
+
+### Optimization Tips
+
+1. **Use provisioned concurrency** for latency-sensitive functions
+2. **Adjust span limits** to reduce memory usage:
+   ```yaml
+   OTEL_SPAN_ATTRIBUTE_COUNT_LIMIT: 32
+   OTEL_SPAN_EVENT_COUNT_LIMIT: 32
+   ```
+3. **Use sampling** in high-volume environments
+4. **Disable unused instrumentations**:
+   ```yaml
+   OTEL_INSTRUMENTATION_AWS_LAMBDA_ENABLED: true
+   OTEL_INSTRUMENTATION_HTTP_ENABLED: true
+   OTEL_INSTRUMENTATION_AWS_SDK_ENABLED: false
+   ```
+
+## Troubleshooting
+
+### No Traces Appearing
+
+1. Check CloudWatch Logs for ADOT errors:
+   ```
+   grep "otel" /aws/lambda/your-function
+   ```
+
+2. Verify environment variables:
+   ```bash
+   aws lambda get-function-configuration --function-name your-function \
+     --query 'Environment.Variables'
+   ```
+
+3. Test collector endpoint connectivity:
+   - Ensure Lambda has network access to the collector
+   - Check security groups and NACLs
+   - Verify collector is accepting OTLP HTTP on port 4318
+
+### Wrapper Not Running
+
+Error: `AWS_LAMBDA_EXEC_WRAPPER is set but the wrapper does not exist`
+
+**Solution**: Verify the layer ARN is correct and matches your region.
+
+### Trace Context Not Propagating
+
+1. Ensure `OTEL_PROPAGATORS=tracecontext` is set
+2. Check if HTTP library is supported (axios, node-fetch, http, https)
+3. For unsupported libraries, manually inject headers
+
+### High Cold Start Times
+
+1. Consider using Lambda SnapStart (if available)
+2. Use provisioned concurrency
+3. Minimize layer count (combine layers if possible)
+4. Profile and optimize your application code
+
+## Best Practices
+
+1. **Set meaningful service names**: Use descriptive names that reflect the business function
+2. **Add business context**: Include order IDs, customer IDs, and other relevant attributes
+3. **Handle errors properly**: Record exceptions and set error status on spans
+4. **Use semantic conventions**: Follow OpenTelemetry semantic conventions for consistency
+5. **Monitor collector health**: Ensure your collector is performant and highly available
+6. **Set appropriate sampling**: Balance cost with observability needs
+7. **Use tags for filtering**: Add environment, version, and region as resource attributes
+
+## References
+
+- AWS ADOT Lambda: https://aws-otel.github.io/docs/getting-started/lambda
+- OpenTelemetry Lambda Instrumentation: https://opentelemetry.io/docs/platforms/faas/lambda-auto-instrument/
+- W3C Trace Context: https://www.w3.org/TR/trace-context/
+- OpenTelemetry Semantic Conventions: https://opentelemetry.io/docs/specs/semconv/
diff --git a/ARCHITECTURE.md b/ARCHITECTURE.md
new file mode 100644
index 0000000..ff7e7c2
--- /dev/null
+++ b/ARCHITECTURE.md
@@ -0,0 +1,366 @@
+# Architecture Details
+
+## Service Flow
+
+### 1. Successful Order Flow
+
+```
+Client
+  │
+  │ POST /order
+  ├─────────────────────────────────────────┐
+  │                                         │
+  ▼                                         │
+Order Service                               │
+  │                                         │
+  │ 1. Validate request                     │
+  │ 2. Create root span                     │
+  │                                         │
+  │ POST /inventory (with trace context)    │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Inventory Service               │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Check stock levels       │           │
+  │ 4. Return availability      │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: available=true    │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ POST /payment (with trace context)      │
+  ├─────────────────────────────┐           │
+  │                             │           │
+  ▼                             │           │
+Payment Service                 │           │
+  │                             │           │
+  │ 1. Extract trace context    │           │
+  │ 2. Create child span        │           │
+  │ 3. Process payment          │           │
+  │ 4. Return result            │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: success=true      │           │
+  ▼                             │           │
+Order Service                   │           │
+  │                             │           │
+  │ Complete order processing   │           │
+  │                             │           │
+  └─────────────────────────────┤           │
+  │ Response: 200 OK            │           │
+  ▼                             │           │
+Client ◄──────────────────────────────────────┘
+```
+
+### 2. Out of Stock Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Out of stock detected)
+                       ← 
+         Order Service 
+         (Skip payment, return 409)
+       ←
+Client
+```
+
+### 3. Payment Failure Flow
+
+```
+Client → Order Service → Inventory Service
+                         (Items available)
+                       ← 
+         Order Service → Payment Service
+                         (Payment failed)
+                       ←
+         Order Service
+         (Return 402)
+       ←
+Client
+```
+
+## Trace Structure
+
+### Trace Hierarchy
+
+```
+Trace ID: 00000000000000000000000000000001
+│
+└─ Span: process-order (Order Service)
+   │ Duration: 245ms
+   │ Attributes:
+   │   - order.id: ORD-001
+   │   - customer.id: CUST-123
+   │   - order.items.count: 2
+   │
+   ├─ Span: check-inventory (Order Service)
+   │  │ Duration: 15ms
+   │  │ Attributes:
+   │  │   - service: inventory
+   │  │   - order.id: ORD-001
+   │  │
+   │  └─ Span: HTTP POST (Auto-instrumented)
+   │     │ Duration: 12ms
+   │     │
+   │     └─ Span: check-inventory (Inventory Service)
+   │        Duration: 8ms
+   │        Attributes:
+   │          - inventory.available: true
+   │          - inventory.items.count: 2
+   │
+   └─ Span: process-payment (Order Service)
+      │ Duration: 180ms
+      │ Attributes:
+      │   - service: payment
+      │   - order.id: ORD-001
+      │   - payment.method: credit-card-5555
+      │   - payment.amount: 1059.97
+      │
+      └─ Span: HTTP POST (Auto-instrumented)
+         │ Duration: 175ms
+         │
+         └─ Span: process-payment (Payment Service)
+            Duration: 170ms
+            Attributes:
+              - payment.success: true
+              - payment.transaction_id: txn-1234567890-abc123
+```
+
+## OpenTelemetry Components
+
+### 1. Tracer Provider
+
+Manages the lifecycle of tracers and span processors.
+
+```javascript
+const provider = new NodeTracerProvider({
+  resource: resource,
+});
+```
+
+### 2. OTLP Exporter
+
+Exports spans to OpenTelemetry Collector using HTTP.
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: 'http://localhost:4318/v1/traces',
+});
+```
+
+### 3. Batch Span Processor
+
+Batches spans before export for efficiency.
+
+```javascript
+provider.addSpanProcessor(new BatchSpanProcessor(exporter));
+```
+
+### 4. Auto Instrumentations
+
+Automatically instruments common libraries.
+
+```javascript
+registerInstrumentations({
+  instrumentations: [
+    getNodeAutoInstrumentations({
+      '@opentelemetry/instrumentation-http': { enabled: true },
+      '@opentelemetry/instrumentation-https': { enabled: true },
+    }),
+  ],
+});
+```
+
+## Trace Context Propagation
+
+### W3C Trace Context Format
+
+```
+traceparent: 00-<trace-id>-<span-id>-<trace-flags>
+
+Example:
+traceparent: 00-4bf92f3577b34da6a3ce929d0e0e4736-00f067aa0ba902b7-01
+            │  │                                │                │
+            │  └─ Trace ID (32 hex chars)      │                └─ Flags
+            │                                   └─ Parent Span ID (16 hex chars)
+            └─ Version (00)
+```
+
+### Context Injection
+
+When Order Service calls Inventory Service:
+
+```javascript
+// Order Service
+const headers = injectTraceContext();
+// headers = { traceparent: '00-...-...-01' }
+
+axios.post(inventoryUrl, data, { headers });
+```
+
+### Context Extraction
+
+When Inventory Service receives request:
+
+```javascript
+// Inventory Service
+const traceContext = extractTraceContext(event);
+// Continue the trace with the same trace ID
+```
+
+## Span Attributes
+
+### Semantic Conventions
+
+Following OpenTelemetry semantic conventions:
+
+| Attribute | Description | Example |
+|-----------|-------------|---------|
+| `service.name` | Service identifier | `order-service` |
+| `service.version` | Service version | `1.0.0` |
+| `deployment.environment` | Environment | `production` |
+| `order.id` | Order identifier | `ORD-001` |
+| `customer.id` | Customer identifier | `CUST-123` |
+| `payment.amount` | Payment amount | `1059.97` |
+| `payment.method` | Payment method | `credit-card-5555` |
+| `inventory.available` | Availability flag | `true` |
+| `http.method` | HTTP method | `POST` |
+| `http.status_code` | HTTP status | `200` |
+
+## Error Handling
+
+### Error Span Status
+
+```javascript
+span.setStatus({
+  code: api.SpanStatusCode.ERROR,
+  message: error.message,
+});
+span.recordException(error);
+```
+
+### Business Logic Errors vs Technical Errors
+
+- **Business Logic Errors** (out of stock, payment declined):
+  - Span status: OK
+  - Custom attributes indicate business failure
+  - Example: `inventory.available: false`
+
+- **Technical Errors** (network failure, invalid input):
+  - Span status: ERROR
+  - Exception recorded
+  - Stack trace captured
+
+## Performance Considerations
+
+### Batch Processing
+
+Spans are batched before export to reduce network overhead:
+
+```javascript
+new BatchSpanProcessor(exporter, {
+  maxQueueSize: 2048,
+  maxExportBatchSize: 512,
+  scheduledDelayMillis: 5000,
+})
+```
+
+### Sampling
+
+For high-volume systems, implement sampling:
+
+```javascript
+const sampler = new TraceIdRatioBasedSampler(0.1); // 10% sampling
+const provider = new NodeTracerProvider({
+  resource: resource,
+  sampler: sampler,
+});
+```
+
+### Async Export
+
+Span export is asynchronous and doesn't block Lambda execution.
+
+## Security
+
+### Securing OTLP Endpoint
+
+```javascript
+const exporter = new OTLPTraceExporter({
+  url: process.env.OTEL_EXPORTER_OTLP_ENDPOINT,
+  headers: {
+    'Authorization': `Bearer ${process.env.OTEL_API_KEY}`,
+  },
+});
+```
+
+### Data Privacy
+
+- Avoid capturing sensitive data in spans
+- Redact PII from span attributes
+- Use attribute filtering in the collector
+
+## Monitoring and Alerting
+
+### Key Metrics to Monitor
+
+1. **Trace Completeness**
+   - Percentage of complete traces
+   - Missing spans
+
+2. **Error Rates**
+   - Spans with ERROR status
+   - Service-specific error rates
+
+3. **Latency**
+   - P50, P95, P99 latencies
+   - Per-service latency breakdown
+
+4. **Business Metrics**
+   - Order success rate
+   - Payment failure rate
+   - Inventory unavailability rate
+
+### Example Queries (Jaeger)
+
+```
+# Find all failed orders
+service="order-service" AND error=true
+
+# Find orders with payment failures
+service="payment-service" AND payment.success=false
+
+# Find slow orders (> 1s)
+service="order-service" AND duration>1000ms
+
+# Find out-of-stock scenarios
+service="inventory-service" AND inventory.available=false
+```
+
+## Troubleshooting
+
+### Common Issues
+
+1. **Traces not appearing**
+   - Check OTLP endpoint connectivity
+   - Verify Lambda has network access
+   - Check CloudWatch logs for export errors
+
+2. **Broken traces**
+   - Verify trace context propagation
+   - Check HTTP header forwarding
+   - Ensure consistent trace ID format
+
+3. **High latency**
+   - Review span processor configuration
+   - Check collector performance
+   - Consider async export optimization
+
+4. **Missing spans**
+   - Verify auto-instrumentation is active
+   - Check for exceptions during span creation
+   - Review sampling configuration
diff --git a/DEPLOYMENT-VERIFICATION.md b/DEPLOYMENT-VERIFICATION.md
new file mode 100644
index 0000000..bc2b641
--- /dev/null
+++ b/DEPLOYMENT-VERIFICATION.md
@@ -0,0 +1,286 @@
+# Deployment Verification Guide
+
+This guide helps you verify that the Lambda OpenTelemetry Demo is working correctly.
+
+## Pre-Deployment Checklist
+
+- [ ] Node.js 20.x or later installed
+- [ ] AWS CLI configured with valid credentials
+- [ ] AWS SAM CLI installed
+- [ ] Docker installed (for local testing)
+- [ ] OpenTelemetry backend ready (Jaeger/Zipkin/etc.)
+
+## Quick Deployment Steps
+
+### 1. Start OpenTelemetry Backend
+
+```bash
+# Start Jaeger with Docker Compose
+docker-compose up -d jaeger
+
+# Verify Jaeger is running
+curl http://localhost:16686
+```
+
+### 2. Update Layer ARN
+
+Edit `template.yaml` and update the `AdotLayerArn` parameter for your region:
+
+```yaml
+AdotLayerArn:
+  Default: 'arn:aws:lambda:YOUR-REGION:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5'
+```
+
+Find ARNs for your region: https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+### 3. Build and Deploy
+
+```bash
+# Install dependencies
+npm install
+
+# Build Lambda functions
+sam build
+
+# Deploy to AWS
+sam deploy --guided
+```
+
+During deployment, provide:
+- **Stack name**: `lambda-otel-demo`
+- **AWS Region**: Your preferred region (e.g., `us-east-1`)
+- **OtelCollectorEndpoint**: Your collector URL (e.g., `http://your-collector:4318`)
+- **Environment**: `production` or `development`
+- **AdotLayerArn**: ARN for your region
+- Confirm changes: `y`
+
+### 4. Note Deployment Outputs
+
+Save these outputs from the deployment:
+- `ApiEndpoint` - Base API Gateway URL
+- `OrderServiceUrl` - Order service endpoint
+- `InventoryServiceUrl` - Inventory service endpoint
+- `PaymentServiceUrl` - Payment service endpoint
+
+## Verification Tests
+
+### Test 1: Successful Order ✅
+
+```bash
+curl -X POST https://YOUR-API-ENDPOINT/Prod/order \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+```
+
+**Expected Response**: HTTP 200 with `"success": true`
+
+### Test 2: Out of Stock ⚠️
+
+```bash
+curl -X POST https://YOUR-API-ENDPOINT/Prod/order \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      }
+    ]
+  }'
+```
+
+**Expected Response**: HTTP 409 with `"error": "Items out of stock"`
+
+### Test 3: Payment Failure 💳
+
+```bash
+curl -X POST https://YOUR-API-ENDPOINT/Prod/order \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+```
+
+**Expected Response**: HTTP 402 with `"error": "Payment failed"`
+
+### Test 4: Automated Test Script
+
+```bash
+# Run all tests at once
+./test-api.sh https://YOUR-API-ENDPOINT/Prod
+```
+
+## Trace Verification
+
+### 1. Access Jaeger UI
+
+Open http://localhost:16686 in your browser
+
+### 2. Search for Traces
+
+- **Service**: Select `order-service`
+- **Operation**: Select `process-order`
+- Click **Find Traces**
+
+### 3. Verify Trace Structure
+
+A successful order trace should show:
+
+```
+order-service: process-order (root span)
+├── order-service: check-inventory
+│   └── HTTP POST
+│       └── inventory-service: check-inventory
+└── order-service: process-payment
+    └── HTTP POST
+        └── payment-service: process-payment
+```
+
+### 4. Verify Span Attributes
+
+Click on a span and verify these attributes are present:
+
+**Order Service Span:**
+- `order.id`
+- `customer.id`
+- `order.items.count`
+- `payment.method`
+
+**Inventory Service Span:**
+- `inventory.all_available`
+- `inventory.items.count`
+
+**Payment Service Span:**
+- `payment.success`
+- `payment.amount`
+- `payment.transaction_id`
+
+## Common Issues and Solutions
+
+### Issue: No traces appearing
+
+**Solutions:**
+1. Check CloudWatch Logs for Lambda errors:
+   ```bash
+   aws logs tail /aws/lambda/order-service --follow
+   ```
+
+2. Verify ADOT Layer is attached:
+   ```bash
+   aws lambda get-function --function-name order-service \
+     --query 'Configuration.Layers'
+   ```
+
+3. Verify environment variables:
+   ```bash
+   aws lambda get-function-configuration --function-name order-service \
+     --query 'Environment.Variables'
+   ```
+
+4. Test collector connectivity (if using VPC):
+   - Ensure Lambda functions have VPC access
+   - Check security groups allow outbound traffic to collector
+   - Verify collector is listening on correct port
+
+### Issue: Trace context not propagating
+
+**Solutions:**
+1. Verify `OTEL_PROPAGATORS=tracecontext` is set
+2. Check API Gateway is passing headers through
+3. Verify axios version is compatible (should be 1.13.5)
+
+### Issue: High cold start times
+
+**Solutions:**
+1. Use provisioned concurrency for latency-sensitive functions
+2. Increase Lambda memory (reduces cold start time)
+3. Consider Lambda SnapStart if available in your region
+
+### Issue: Service URLs incorrect
+
+**Solutions:**
+1. Verify API Gateway is deployed correctly
+2. Check environment variables `INVENTORY_SERVICE_URL` and `PAYMENT_SERVICE_URL`
+3. Ensure API Gateway stage is `Prod`
+
+## Performance Benchmarks
+
+Expected performance metrics:
+
+| Metric | Value |
+|--------|-------|
+| Cold Start | 800-1200ms |
+| Warm Invocation | 50-150ms |
+| Trace Export Overhead | <5ms |
+| E2E Order Processing | 200-500ms |
+
+## Cleanup
+
+To remove all resources:
+
+```bash
+# Delete the CloudFormation stack
+sam delete --stack-name lambda-otel-demo
+
+# Stop Jaeger
+docker-compose down
+
+# Clean build artifacts
+rm -rf .aws-sam node_modules
+```
+
+## Next Steps
+
+1. **Configure Sampling**: Update `OTEL_TRACES_SAMPLER` for production
+2. **Add Alerting**: Set up CloudWatch alarms for Lambda errors
+3. **Monitor Costs**: Track Lambda invocations and data transfer
+4. **Customize Inventory**: Modify mock inventory in `src/inventory-service/index.js`
+5. **Add More Scenarios**: Create additional test cases for your use case
+
+## Support
+
+For issues or questions:
+- Review [README.md](./README.md) for detailed documentation
+- Check [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md) for configuration details
+- Review [ARCHITECTURE.md](./ARCHITECTURE.md) for technical details
+- Check AWS ADOT documentation: https://aws-otel.github.io/
+- OpenTelemetry documentation: https://opentelemetry.io/docs/
+
+## Success Criteria
+
+✅ All 3 Lambda functions deployed successfully  
+✅ API Gateway endpoints accessible  
+✅ Test scenarios return expected responses  
+✅ Traces visible in backend UI  
+✅ Trace context propagates across services  
+✅ Span attributes contain business data  
+✅ Error scenarios traced correctly  
+
+Congratulations! Your Lambda OpenTelemetry Demo is fully operational! 🎉
diff --git a/README.md b/README.md
index 11f8c55..aff152d 100644
--- a/README.md
+++ b/README.md
@@ -1,2 +1,476 @@
-# lambda-opentelemetry-demo
-Sample lambda project demonstrating how to instrument lambda with OpenTelemetry
+# Lambda OpenTelemetry Demo
+
+A comprehensive AWS Lambda project demonstrating how to integrate OpenTelemetry for end-to-end distributed tracing across multiple microservices **without using AWS CloudWatch or X-Ray**, using the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation.
+
+## 🎯 Overview
+
+This project implements a realistic e-commerce order processing workflow using three Lambda functions representing distinct microservices:
+
+1. **Order Service** - Orchestrates the order processing workflow
+2. **Inventory Service** - Validates item availability
+3. **Payment Service** - Processes payments
+
+The services communicate with each other while propagating trace context using OpenTelemetry, enabling complete visibility into request flows across all services.
+
+## 🏗️ Architecture
+
+```
+┌─────────────────┐
+│  Order Service  │
+│   (Lambda)      │
+└────────┬────────┘
+         │
+         ├──────────────────┐
+         │                  │
+         ▼                  ▼
+┌─────────────────┐  ┌─────────────────┐
+│ Inventory Svc   │  │  Payment Svc    │
+│   (Lambda)      │  │   (Lambda)      │
+└─────────────────┘  └─────────────────┘
+         │                  │
+         └──────┬───────────┘
+                ▼
+        OpenTelemetry
+         Collector
+                │
+                ▼
+        Tracing Backend
+      (Jaeger/Zipkin/etc)
+```
+
+## ✨ Features
+
+- ✅ **AWS ADOT Lambda Layer** - Uses AWS Distro for OpenTelemetry Lambda Layer for zero-code instrumentation
+- ✅ **Automatic Instrumentation** - Auto-instruments Lambda, HTTP/HTTPS, and AWS SDK without code changes
+- ✅ **Distributed Tracing** - End-to-end trace propagation across Lambda functions
+- ✅ **W3C Trace Context** - Standard trace context propagation using W3C format
+- ✅ **OTLP Export** - Exports traces using OTLP HTTP protocol
+- ✅ **Custom Spans** - Manual span creation for business logic insights
+- ✅ **No CloudWatch/X-Ray** - Direct export to any OpenTelemetry-compatible backend
+- ✅ **Error Scenarios** - Built-in test scenarios for:
+  - Out of stock items
+  - Payment failures (card declined, insufficient funds)
+  - Network errors
+
+## 📋 Prerequisites
+
+- Node.js 18.x or later
+- AWS CLI configured with appropriate credentials
+- AWS SAM CLI for deployment
+- OpenTelemetry Collector or compatible backend (Jaeger, Zipkin, etc.)
+
+## 🚀 Quick Start
+
+### 1. Install Dependencies
+
+```bash
+npm install
+```
+
+### 2. Set Up OpenTelemetry Backend
+
+You need an OpenTelemetry-compatible backend to receive and visualize traces. Here are some options:
+
+#### Option A: Jaeger (Recommended for local testing)
+
+```bash
+# Run Jaeger all-in-one with Docker (or use docker-compose)
+docker-compose up -d jaeger
+
+# Or manually:
+docker run -d --name jaeger \
+  -e COLLECTOR_OTLP_ENABLED=true \
+  -p 16686:16686 \
+  -p 4318:4318 \
+  jaegertracing/all-in-one:latest
+
+# Access Jaeger UI at http://localhost:16686
+```
+
+#### Option B: Zipkin
+
+```bash
+# Run Zipkin with Docker
+docker run -d --name zipkin \
+  -p 9411:9411 \
+  openzipkin/zipkin:latest
+
+# Note: You'll need an OpenTelemetry Collector to convert OTLP to Zipkin format
+```
+
+#### Option C: Grafana Cloud, Honeycomb, or other SaaS providers
+
+Configure the OTEL_EXPORTER_OTLP_ENDPOINT parameter with your provider's endpoint.
+
+### 3. Update Lambda Layer ARN
+
+**Important**: Update the `AdotLayerArn` parameter in `template.yaml` with the correct ARN for your AWS region.
+
+Find the latest ARN for your region here:
+- https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Example ARNs:
+- **us-east-1**: `arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **us-west-2**: `arn:aws:lambda:us-west-2:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+- **eu-west-1**: `arn:aws:lambda:eu-west-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5`
+
+See [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md) for complete list.
+
+### 4. Deploy to AWS
+
+```bash
+# Build the Lambda functions
+sam build
+
+# Deploy (follow the prompts)
+sam deploy --guided
+
+# Note the API endpoint from the outputs
+```
+
+During `sam deploy --guided`, you'll be prompted to provide:
+- **Stack name** (e.g., `lambda-otel-demo`)
+- **AWS Region** (e.g., `us-east-1`)
+- **OtelCollectorEndpoint** - Your OpenTelemetry Collector endpoint without `/v1/traces` (e.g., `http://your-collector:4318`)
+- **Environment** - Deployment environment (e.g., `production`, `staging`)
+- **AdotLayerArn** - AWS ADOT Lambda Layer ARN for your region
+- Confirm changes before deployment
+
+**Note**: If you're using a collector in a VPC, ensure your Lambda functions have VPC access configured.
+
+### 5. Test the Services
+
+Use the provided test script:
+
+```bash
+# Replace with your actual API endpoint from SAM deploy output
+./test-api.sh https://your-api-id.execute-api.region.amazonaws.com/Prod
+```
+
+Or manually test with curl:
+
+```bash
+# Successful order
+curl -X POST https://your-api-endpoint/Prod/order \
+  -H "Content-Type: application/json" \
+  -d @test-payloads.json
+```
+
+### 6. View Traces
+
+Open your tracing backend UI:
+- Jaeger: http://localhost:16686
+- Select service: `order-service`
+- Click "Find Traces" to view the end-to-end traces
+
+## 🔧 AWS ADOT Lambda Layer
+
+This project uses the **AWS Distro for OpenTelemetry (ADOT) Lambda Layer** for automatic instrumentation. The layer provides:
+
+### Key Benefits
+
+1. **Zero-Code Instrumentation** - Auto-instruments your Lambda function without code changes
+2. **No Dependency Bundling** - OpenTelemetry SDKs are provided by the layer, reducing deployment package size
+3. **Automatic Context Propagation** - Trace context is automatically propagated across service calls
+4. **AWS-Optimized** - Maintained and supported by AWS with regular updates
+
+### How It Works
+
+The layer works through the `AWS_LAMBDA_EXEC_WRAPPER` environment variable:
+
+```yaml
+Environment:
+  Variables:
+    AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler  # Enables auto-instrumentation
+    OTEL_SERVICE_NAME: order-service              # Service identifier
+    OTEL_TRACES_SAMPLER: AlwaysOn                 # Sampling strategy
+    OTEL_EXPORTER_OTLP_ENDPOINT: http://collector:4318
+```
+
+When your Lambda function is invoked:
+1. The wrapper initializes OpenTelemetry SDK
+2. Auto-instrumentation is activated for HTTP, AWS SDK, and Lambda runtime
+3. A root span is created for the Lambda invocation
+4. Your handler executes within the trace context
+5. Spans are exported to your configured OTLP endpoint
+
+### What Gets Instrumented Automatically
+
+- ✅ Lambda function invocations
+- ✅ HTTP/HTTPS requests (axios, node-fetch, native http/https)
+- ✅ AWS SDK v2 and v3 calls
+- ✅ Database clients (when using instrumented libraries)
+- ✅ Trace context propagation in headers
+
+### Adding Custom Instrumentation
+
+While the layer handles most instrumentation automatically, you can add custom spans for business logic:
+
+```javascript
+const api = require('@opentelemetry/api');
+
+exports.handler = async (event) => {
+  const tracer = api.trace.getTracer('my-service');
+  
+  return tracer.startActiveSpan('custom-operation', async (span) => {
+    span.setAttribute('business.attribute', 'value');
+    // Your logic here
+    span.end();
+  });
+};
+```
+
+For detailed configuration options, see [ADOT-LAYER-CONFIG.md](./ADOT-LAYER-CONFIG.md).
+
+## 📝 Test Scenarios
+
+### Scenario 1: Successful Order ✅
+
+Tests the happy path where all services succeed.
+
+```json
+{
+  "orderId": "ORD-001",
+  "customerId": "CUST-123",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-001",
+      "name": "Laptop",
+      "quantity": 1,
+      "price": 999.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Success)
+- Order completed with HTTP 200
+
+### Scenario 2: Out of Stock ⚠️
+
+Tests inventory unavailability.
+
+```json
+{
+  "orderId": "ORD-002",
+  "customerId": "CUST-456",
+  "paymentMethod": "credit-card-5555",
+  "items": [
+    {
+      "itemId": "item-003",
+      "name": "Keyboard",
+      "quantity": 1,
+      "price": 79.99
+    }
+  ]
+}
+```
+
+**Expected Trace:**
+- Order Service → Inventory Service (Out of stock detected)
+- Payment Service NOT called
+- Order fails with HTTP 409
+
+**Out of Stock Items:**
+- `item-003` - Keyboard (0 in stock)
+- `item-005` - Headphones (0 in stock)
+
+### Scenario 3: Payment Failure 💳
+
+Tests payment processing failures.
+
+**Card Declined:**
+```json
+{
+  "orderId": "ORD-003",
+  "customerId": "CUST-789",
+  "paymentMethod": "4111111111111111",
+  "items": [{"itemId": "item-001", "quantity": 1, "price": 999.99}]
+}
+```
+
+**Insufficient Funds:**
+```json
+{
+  "orderId": "ORD-004",
+  "customerId": "CUST-999",
+  "paymentMethod": "4222222222222222",
+  "items": [{"itemId": "item-004", "quantity": 2, "price": 399.99}]
+}
+```
+
+**Test Payment Methods:**
+- `4111111111111111` - Card declined
+- `4222222222222222` - Insufficient funds
+- `4333333333333333` - Expired card
+- Any other value - Success (with 10% random failure rate)
+
+**Expected Trace:**
+- Order Service → Inventory Service (Success)
+- Order Service → Payment Service (Payment fails)
+- Order fails with HTTP 402
+
+## 🔍 Understanding the Traces
+
+Each trace will show:
+
+1. **Span Attributes:**
+   - Order ID, Customer ID
+   - Item counts and details
+   - Payment amounts and methods
+   - Service names and versions
+   - Success/failure reasons
+
+2. **Span Hierarchy:**
+   ```
+   process-order (Order Service)
+   ├── check-inventory (Order Service -> Inventory Service)
+   │   └── check-inventory (Inventory Service)
+   └── process-payment (Order Service -> Payment Service)
+       └── process-payment (Payment Service)
+   ```
+
+3. **Trace Context Propagation:**
+   - Trace IDs are consistent across all services
+   - Parent-child relationships are maintained
+   - W3C traceparent headers are used
+
+## 🛠️ Configuration
+
+### Environment Variables
+
+Configure these in the SAM template or Lambda console:
+
+- `OTEL_EXPORTER_OTLP_ENDPOINT` - OpenTelemetry Collector endpoint (default: `http://localhost:4318/v1/traces`)
+- `ENVIRONMENT` - Deployment environment (default: `development`)
+- `INVENTORY_SERVICE_URL` - Inventory service endpoint
+- `PAYMENT_SERVICE_URL` - Payment service endpoint
+
+### Inventory Configuration
+
+Modify the mock inventory in `src/inventory-service/index.js`:
+
+```javascript
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  // Add more items...
+};
+```
+
+### Payment Configuration
+
+Modify failure patterns in `src/payment-service/index.js`:
+
+```javascript
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  // Add more patterns...
+};
+```
+
+## 📂 Project Structure
+
+```
+lambda-opentelemetry-demo/
+├── src/
+│   ├── order-service/          # Order orchestration service
+│   │   └── index.js
+│   ├── inventory-service/      # Inventory check service
+│   │   └── index.js
+│   ├── payment-service/        # Payment processing service
+│   │   └── index.js
+│   └── shared/                 # Shared utilities
+│       ├── tracer.js           # OpenTelemetry setup
+│       └── utils.js            # Common utilities
+├── template.yaml               # AWS SAM template
+├── package.json                # Node.js dependencies
+├── test-payloads.json          # Sample test data
+├── test-api.sh                 # API test script
+└── README.md                   # This file
+```
+
+## 🔧 Local Development
+
+To test locally without deploying to AWS:
+
+1. Start your OpenTelemetry backend (e.g., Jaeger)
+2. Use AWS SAM Local:
+
+```bash
+sam build
+sam local start-api --env-vars env.json
+```
+
+Create `env.json`:
+```json
+{
+  "Parameters": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "INVENTORY_SERVICE_URL": "http://host.docker.internal:3000/inventory",
+    "PAYMENT_SERVICE_URL": "http://host.docker.internal:3000/payment"
+  }
+}
+```
+
+## 📊 Observability Best Practices
+
+This demo demonstrates several observability best practices:
+
+1. **Structured Logging** - Logs include trace context for correlation
+2. **Semantic Attributes** - Meaningful span attributes for filtering and analysis
+3. **Error Handling** - Errors are captured as span events
+4. **Business Context** - Business-relevant data in spans (order IDs, amounts, etc.)
+5. **Service Naming** - Clear service names for easy identification
+6. **Context Propagation** - W3C standard trace context across service boundaries
+
+## 🔐 Security Considerations
+
+- This is a demo project - do not use in production without proper security hardening
+- Implement proper authentication/authorization for API endpoints
+- Secure OpenTelemetry Collector endpoints
+- Use AWS Secrets Manager for sensitive configuration
+- Enable API Gateway throttling and request validation
+
+## 🤝 Contributing
+
+Contributions are welcome! Please feel free to submit a Pull Request.
+
+## 📄 License
+
+MIT License - See LICENSE file for details
+
+## 🎓 Learning Resources
+
+- [OpenTelemetry Documentation](https://opentelemetry.io/docs/)
+- [AWS Lambda Best Practices](https://docs.aws.amazon.com/lambda/latest/dg/best-practices.html)
+- [W3C Trace Context](https://www.w3.org/TR/trace-context/)
+- [Distributed Tracing Guide](https://opentelemetry.io/docs/concepts/signals/traces/)
+
+## 🐛 Troubleshooting
+
+### Traces not appearing in backend
+
+- Verify OTEL_EXPORTER_OTLP_ENDPOINT is correctly configured
+- Check Lambda logs in CloudWatch for errors
+- Ensure OpenTelemetry Collector/backend is running and accessible
+- Verify network connectivity between Lambda and collector
+
+### Service-to-service calls failing
+
+- Check that service URLs are correctly configured
+- Verify API Gateway endpoints are deployed
+- Review Lambda function logs for errors
+- Check IAM permissions if using private endpoints
+
+### High latency or timeouts
+
+- Increase Lambda timeout in template.yaml
+- Check OpenTelemetry Collector performance
+- Consider using asynchronous export
+- Review batch span processor configuration
diff --git a/docker-compose.yaml b/docker-compose.yaml
new file mode 100644
index 0000000..7f969f4
--- /dev/null
+++ b/docker-compose.yaml
@@ -0,0 +1,37 @@
+version: '3.8'
+
+services:
+  # Jaeger all-in-one with OTLP support
+  jaeger:
+    image: jaegertracing/all-in-one:latest
+    container_name: jaeger-otel
+    environment:
+      - COLLECTOR_OTLP_ENABLED=true
+      - LOG_LEVEL=debug
+    ports:
+      - "16686:16686"  # Jaeger UI
+      - "4318:4318"    # OTLP HTTP receiver
+      - "4317:4317"    # OTLP gRPC receiver
+      - "14268:14268"  # Jaeger collector HTTP
+      - "14250:14250"  # Jaeger collector gRPC
+    networks:
+      - otel-demo
+
+  # Optional: OpenTelemetry Collector (if you want to use a separate collector)
+  # otel-collector:
+  #   image: otel/opentelemetry-collector-contrib:latest
+  #   container_name: otel-collector
+  #   command: ["--config=/etc/otel-collector-config.yaml"]
+  #   volumes:
+  #     - ./otel-collector-config.yaml:/etc/otel-collector-config.yaml
+  #   ports:
+  #     - "4318:4318"    # OTLP HTTP receiver
+  #     - "4317:4317"    # OTLP gRPC receiver
+  #     - "8888:8888"    # Prometheus metrics
+  #     - "13133:13133"  # Health check
+  #   networks:
+  #     - otel-demo
+
+networks:
+  otel-demo:
+    driver: bridge
diff --git a/env.json b/env.json
new file mode 100644
index 0000000..67b70e4
--- /dev/null
+++ b/env.json
@@ -0,0 +1,16 @@
+{
+  "OrderServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local",
+    "INVENTORY_SERVICE_URL": "http://127.0.0.1:3001/inventory",
+    "PAYMENT_SERVICE_URL": "http://127.0.0.1:3002/payment"
+  },
+  "InventoryServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  },
+  "PaymentServiceFunction": {
+    "OTEL_EXPORTER_OTLP_ENDPOINT": "http://host.docker.internal:4318/v1/traces",
+    "ENVIRONMENT": "local"
+  }
+}
diff --git a/local-test.sh b/local-test.sh
new file mode 100755
index 0000000..8b43c30
--- /dev/null
+++ b/local-test.sh
@@ -0,0 +1,53 @@
+#!/bin/bash
+
+# Simple local testing script using SAM Local
+# This script starts SAM local API and runs tests
+
+set -e
+
+echo "Starting Lambda OpenTelemetry Demo Local Test"
+echo "=============================================="
+echo ""
+
+# Check if Docker is running
+if ! docker info > /dev/null 2>&1; then
+    echo "Error: Docker is not running. Please start Docker first."
+    exit 1
+fi
+
+# Check if Jaeger is running
+if ! docker ps | grep -q jaeger-otel; then
+    echo "Starting Jaeger..."
+    docker-compose up -d jaeger
+    echo "Waiting for Jaeger to be ready..."
+    sleep 5
+else
+    echo "Jaeger is already running"
+fi
+
+echo ""
+echo "Jaeger UI available at: http://localhost:16686"
+echo ""
+
+# Build the Lambda functions
+echo "Building Lambda functions..."
+sam build
+
+if [ $? -ne 0 ]; then
+    echo "Error: Build failed"
+    exit 1
+fi
+
+echo ""
+echo "Lambda functions built successfully!"
+echo ""
+echo "To test the API:"
+echo "1. Start SAM local API in one terminal:"
+echo "   sam local start-api --env-vars env.json"
+echo ""
+echo "2. In another terminal, run the test script:"
+echo "   ./test-api.sh http://127.0.0.1:3000"
+echo ""
+echo "3. View traces in Jaeger UI:"
+echo "   http://localhost:16686"
+echo ""
diff --git a/package-lock.json b/package-lock.json
new file mode 100644
index 0000000..eeb2106
--- /dev/null
+++ b/package-lock.json
@@ -0,0 +1,295 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "lockfileVersion": 3,
+  "requires": true,
+  "packages": {
+    "": {
+      "name": "lambda-opentelemetry-demo",
+      "version": "1.0.0",
+      "license": "MIT",
+      "dependencies": {
+        "axios": "^1.13.5"
+      }
+    },
+    "node_modules/asynckit": {
+      "version": "0.4.0",
+      "resolved": "https://registry.npmjs.org/asynckit/-/asynckit-0.4.0.tgz",
+      "integrity": "sha512-Oei9OH4tRh0YqU3GxhX79dM/mwVgvbZJaSNaRk+bshkj0S5cfHcgYakreBjrHwatXKbz+IoIdYLxrKim2MjW0Q==",
+      "license": "MIT"
+    },
+    "node_modules/axios": {
+      "version": "1.13.5",
+      "resolved": "https://registry.npmjs.org/axios/-/axios-1.13.5.tgz",
+      "integrity": "sha512-cz4ur7Vb0xS4/KUN0tPWe44eqxrIu31me+fbang3ijiNscE129POzipJJA6zniq2C/Z6sJCjMimjS8Lc/GAs8Q==",
+      "license": "MIT",
+      "dependencies": {
+        "follow-redirects": "^1.15.11",
+        "form-data": "^4.0.5",
+        "proxy-from-env": "^1.1.0"
+      }
+    },
+    "node_modules/call-bind-apply-helpers": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/call-bind-apply-helpers/-/call-bind-apply-helpers-1.0.2.tgz",
+      "integrity": "sha512-Sp1ablJ0ivDkSzjcaJdxEunN5/XvksFJ2sMBFfq6x0ryhQV/2b/KwFe21cMpmHtPOSij8K99/wSfoEuTObmuMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/combined-stream": {
+      "version": "1.0.8",
+      "resolved": "https://registry.npmjs.org/combined-stream/-/combined-stream-1.0.8.tgz",
+      "integrity": "sha512-FQN4MRfuJeHf7cBbBMJFXhKSDq+2kAArBlmRBvcvFE5BB1HZKXtSFASDhdlz9zOYwxh8lDdnvmMOe/+5cdoEdg==",
+      "license": "MIT",
+      "dependencies": {
+        "delayed-stream": "~1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.8"
+      }
+    },
+    "node_modules/delayed-stream": {
+      "version": "1.0.0",
+      "resolved": "https://registry.npmjs.org/delayed-stream/-/delayed-stream-1.0.0.tgz",
+      "integrity": "sha512-ZySD7Nf91aLB0RxL4KGrKHBXl7Eds1DAmEdcoVawXnLD7SDhpNgtuII2aAkg7a7QS41jxPSZ17p4VdGnMHk3MQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">=0.4.0"
+      }
+    },
+    "node_modules/dunder-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/dunder-proto/-/dunder-proto-1.0.1.tgz",
+      "integrity": "sha512-KIN/nDJBQRcXw0MLVhZE9iQHmG68qAVIBg9CqmUYjmQIhgij9U5MFvrqkUL5FbtyyzZuOeOt0zdeRe4UY7ct+A==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "gopd": "^1.2.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-define-property": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/es-define-property/-/es-define-property-1.0.1.tgz",
+      "integrity": "sha512-e3nRfgfUZ4rNGL232gUgX06QNyyez04KdjFrF+LTRoOXmrOgFKDg4BCdsjW8EnT69eqdYGmRpJwiPVYNrCaW3g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-errors": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/es-errors/-/es-errors-1.3.0.tgz",
+      "integrity": "sha512-Zf5H2Kxt2xjTvbJvP2ZWLEICxA6j+hAmMzIlypy4xcBg1vKVnx89Wy0GbS+kf5cwCVFFzdCFh2XSCFNULS6csw==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-object-atoms": {
+      "version": "1.1.1",
+      "resolved": "https://registry.npmjs.org/es-object-atoms/-/es-object-atoms-1.1.1.tgz",
+      "integrity": "sha512-FGgH2h8zKNim9ljj7dankFPcICIK9Cp5bm+c2gQSYePhpaG5+esrLODihIorn+Pe6FGJzWhXQotPv73jTaldXA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/es-set-tostringtag": {
+      "version": "2.1.0",
+      "resolved": "https://registry.npmjs.org/es-set-tostringtag/-/es-set-tostringtag-2.1.0.tgz",
+      "integrity": "sha512-j6vWzfrGVfyXxge+O0x5sh6cvxAog0a/4Rdd2K36zCMV5eJ+/+tOAngRO8cODMNWbVRdVlmGZQL2YS3yR8bIUA==",
+      "license": "MIT",
+      "dependencies": {
+        "es-errors": "^1.3.0",
+        "get-intrinsic": "^1.2.6",
+        "has-tostringtag": "^1.0.2",
+        "hasown": "^2.0.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/follow-redirects": {
+      "version": "1.15.11",
+      "resolved": "https://registry.npmjs.org/follow-redirects/-/follow-redirects-1.15.11.tgz",
+      "integrity": "sha512-deG2P0JfjrTxl50XGCDyfI97ZGVCxIpfKYmfyrQ54n5FO/0gfIES8C/Psl6kWVDolizcaaxZJnTS0QSMxvnsBQ==",
+      "funding": [
+        {
+          "type": "individual",
+          "url": "https://github.com/sponsors/RubenVerborgh"
+        }
+      ],
+      "license": "MIT",
+      "engines": {
+        "node": ">=4.0"
+      },
+      "peerDependenciesMeta": {
+        "debug": {
+          "optional": true
+        }
+      }
+    },
+    "node_modules/form-data": {
+      "version": "4.0.5",
+      "resolved": "https://registry.npmjs.org/form-data/-/form-data-4.0.5.tgz",
+      "integrity": "sha512-8RipRLol37bNs2bhoV67fiTEvdTrbMUYcFTiy3+wuuOnUog2QBHCZWXDRijWQfAkhBj2Uf5UnVaiWwA5vdd82w==",
+      "license": "MIT",
+      "dependencies": {
+        "asynckit": "^0.4.0",
+        "combined-stream": "^1.0.8",
+        "es-set-tostringtag": "^2.1.0",
+        "hasown": "^2.0.2",
+        "mime-types": "^2.1.12"
+      },
+      "engines": {
+        "node": ">= 6"
+      }
+    },
+    "node_modules/function-bind": {
+      "version": "1.1.2",
+      "resolved": "https://registry.npmjs.org/function-bind/-/function-bind-1.1.2.tgz",
+      "integrity": "sha512-7XHNxH7qX9xG5mIwxkhumTox/MIRNcOgDrxWsMt2pAr23WHp6MrRlN7FBSFpCpr+oVO0F744iUgR82nJMfG2SA==",
+      "license": "MIT",
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-intrinsic": {
+      "version": "1.3.0",
+      "resolved": "https://registry.npmjs.org/get-intrinsic/-/get-intrinsic-1.3.0.tgz",
+      "integrity": "sha512-9fSjSaos/fRIVIp+xSJlE6lfwhES7LNtKaCBIamHsjr2na1BiABJPo0mOjjz8GJDURarmCPGqaiVg5mfjb98CQ==",
+      "license": "MIT",
+      "dependencies": {
+        "call-bind-apply-helpers": "^1.0.2",
+        "es-define-property": "^1.0.1",
+        "es-errors": "^1.3.0",
+        "es-object-atoms": "^1.1.1",
+        "function-bind": "^1.1.2",
+        "get-proto": "^1.0.1",
+        "gopd": "^1.2.0",
+        "has-symbols": "^1.1.0",
+        "hasown": "^2.0.2",
+        "math-intrinsics": "^1.1.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/get-proto": {
+      "version": "1.0.1",
+      "resolved": "https://registry.npmjs.org/get-proto/-/get-proto-1.0.1.tgz",
+      "integrity": "sha512-sTSfBjoXBp89JvIKIefqw7U2CCebsc74kiY6awiGogKtoSGbgjYE/G/+l9sF3MWFPNc9IcoOC4ODfKHfxFmp0g==",
+      "license": "MIT",
+      "dependencies": {
+        "dunder-proto": "^1.0.1",
+        "es-object-atoms": "^1.0.0"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/gopd": {
+      "version": "1.2.0",
+      "resolved": "https://registry.npmjs.org/gopd/-/gopd-1.2.0.tgz",
+      "integrity": "sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-symbols": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/has-symbols/-/has-symbols-1.1.0.tgz",
+      "integrity": "sha512-1cDNdwJ2Jaohmb3sg4OmKaMBwuC48sYni5HUw2DvsC8LjGTLK9h+eb1X6RyuOHe4hT0ULCW68iomhjUoKUqlPQ==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/has-tostringtag": {
+      "version": "1.0.2",
+      "resolved": "https://registry.npmjs.org/has-tostringtag/-/has-tostringtag-1.0.2.tgz",
+      "integrity": "sha512-NqADB8VjPFLM2V0VvHUewwwsw0ZWBaIdgo+ieHtK3hasLz4qeCRjYcqfB6AQrBggRKppKF8L52/VqdVsO47Dlw==",
+      "license": "MIT",
+      "dependencies": {
+        "has-symbols": "^1.0.3"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      },
+      "funding": {
+        "url": "https://github.com/sponsors/ljharb"
+      }
+    },
+    "node_modules/hasown": {
+      "version": "2.0.2",
+      "resolved": "https://registry.npmjs.org/hasown/-/hasown-2.0.2.tgz",
+      "integrity": "sha512-0hJU9SCPvmMzIBdZFqNPXWa6dqh7WdH0cII9y+CyS8rG3nL48Bclra9HmKhVVUHyPWNH5Y7xDwAB7bfgSjkUMQ==",
+      "license": "MIT",
+      "dependencies": {
+        "function-bind": "^1.1.2"
+      },
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/math-intrinsics": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/math-intrinsics/-/math-intrinsics-1.1.0.tgz",
+      "integrity": "sha512-/IXtbwEk5HTPyEwyKX6hGkYXxM9nbj64B+ilVJnC/R6B0pH5G4V3b0pVbL7DBj4tkhBAppbQUlf6F6Xl9LHu1g==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.4"
+      }
+    },
+    "node_modules/mime-db": {
+      "version": "1.52.0",
+      "resolved": "https://registry.npmjs.org/mime-db/-/mime-db-1.52.0.tgz",
+      "integrity": "sha512-sPU4uV7dYlvtWJxwwxHD0PuihVNiE7TyAbQ5SWxDCB9mUYvOgroQOwYQQOKPJ8CIbE+1ETVlOoK1UC2nU3gYvg==",
+      "license": "MIT",
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/mime-types": {
+      "version": "2.1.35",
+      "resolved": "https://registry.npmjs.org/mime-types/-/mime-types-2.1.35.tgz",
+      "integrity": "sha512-ZDY+bPm5zTTF+YpCrAU9nK0UgICYPT0QtT1NZWFv4s++TNkcgVaT0g6+4R2uI4MjQjzysHB1zxuWL50hzaeXiw==",
+      "license": "MIT",
+      "dependencies": {
+        "mime-db": "1.52.0"
+      },
+      "engines": {
+        "node": ">= 0.6"
+      }
+    },
+    "node_modules/proxy-from-env": {
+      "version": "1.1.0",
+      "resolved": "https://registry.npmjs.org/proxy-from-env/-/proxy-from-env-1.1.0.tgz",
+      "integrity": "sha512-D+zkORCbA9f1tdWRK0RaCR3GPv50cMxcrz4X8k5LTSUD1Dkw47mKJEZQNunItRTkWwgtaUSo1RVFRIG9ZXiFYg==",
+      "license": "MIT"
+    }
+  }
+}
diff --git a/package.json b/package.json
new file mode 100644
index 0000000..abe61a7
--- /dev/null
+++ b/package.json
@@ -0,0 +1,23 @@
+{
+  "name": "lambda-opentelemetry-demo",
+  "version": "1.0.0",
+  "description": "Sample AWS Lambda project demonstrating OpenTelemetry integration without CloudWatch/X-Ray",
+  "main": "index.js",
+  "scripts": {
+    "test": "echo \"No tests specified\" && exit 0",
+    "deploy": "sam deploy --guided",
+    "build": "sam build"
+  },
+  "keywords": [
+    "aws",
+    "lambda",
+    "opentelemetry",
+    "tracing",
+    "nodejs"
+  ],
+  "author": "",
+  "license": "MIT",
+  "dependencies": {
+    "axios": "^1.13.5"
+  }
+}
diff --git a/src/inventory-service/index.js b/src/inventory-service/index.js
new file mode 100644
index 0000000..7cb0b00
--- /dev/null
+++ b/src/inventory-service/index.js
@@ -0,0 +1,143 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock inventory database
+const inventory = {
+  'item-001': { name: 'Laptop', quantity: 10 },
+  'item-002': { name: 'Mouse', quantity: 50 },
+  'item-003': { name: 'Keyboard', quantity: 0 },  // Out of stock
+  'item-004': { name: 'Monitor', quantity: 5 },
+  'item-005': { name: 'Headphones', quantity: 0 }, // Out of stock
+};
+
+/**
+ * Inventory Service Lambda Handler
+ * This service checks if requested items are available in inventory
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Inventory Service received event:', JSON.stringify(event));
+
+  return withSpan('check-inventory', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, items } = body;
+
+      // Validate input
+      if (!orderId || !items || !Array.isArray(items)) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing or invalid required fields',
+        });
+        return createResponse(400, {
+          available: false,
+          error: 'Missing or invalid required fields: orderId, items (array)',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'inventory.items.count': items.length,
+      });
+
+      console.log(`Checking inventory for order ${orderId}`);
+
+      // Check each item
+      const unavailableItems = [];
+      let allAvailable = true;
+
+      for (const item of items) {
+        const { itemId, quantity } = item;
+        
+        if (!itemId || !quantity) {
+          continue;
+        }
+
+        addSpanAttributes({
+          [`inventory.item.${itemId}.requested`]: quantity,
+        });
+
+        // Check if item exists in inventory
+        if (!inventory[itemId]) {
+          console.log(`Item ${itemId} not found in inventory`);
+          unavailableItems.push({
+            itemId,
+            reason: 'Item not found',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'not-found',
+          });
+          continue;
+        }
+
+        const availableQuantity = inventory[itemId].quantity;
+        addSpanAttributes({
+          [`inventory.item.${itemId}.available`]: availableQuantity,
+        });
+
+        // Check if sufficient quantity is available
+        if (availableQuantity < quantity) {
+          console.log(`Insufficient quantity for item ${itemId}. Requested: ${quantity}, Available: ${availableQuantity}`);
+          unavailableItems.push({
+            itemId,
+            name: inventory[itemId].name,
+            requestedQuantity: quantity,
+            availableQuantity: availableQuantity,
+            reason: availableQuantity === 0 ? 'Out of stock' : 'Insufficient quantity',
+          });
+          allAvailable = false;
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'insufficient',
+          });
+        } else {
+          console.log(`Item ${itemId} is available. Requested: ${quantity}, Available: ${availableQuantity}`);
+          addSpanAttributes({
+            [`inventory.item.${itemId}.status`]: 'available',
+          });
+        }
+      }
+
+      addSpanAttributes({
+        'inventory.all_available': allAvailable,
+        'inventory.unavailable_count': unavailableItems.length,
+      });
+
+      if (allAvailable) {
+        console.log(`All items available for order ${orderId}`);
+        
+        return createResponse(200, {
+          available: true,
+          orderId,
+          message: 'All items are available',
+        });
+      } else {
+        console.log(`Some items unavailable for order ${orderId}:`, unavailableItems);
+        addSpanAttributes({
+          'inventory.failure_reason': 'items-unavailable',
+        });
+        
+        return createResponse(200, {
+          available: false,
+          orderId,
+          unavailableItems,
+          message: 'Some items are not available',
+        });
+      }
+
+    } catch (error) {
+      console.error('Inventory check error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        available: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/src/order-service/index.js b/src/order-service/index.js
new file mode 100644
index 0000000..7d05578
--- /dev/null
+++ b/src/order-service/index.js
@@ -0,0 +1,181 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { callService, createResponse } = require('../shared/utils');
+
+/**
+ * Order Service Lambda Handler
+ * This service accepts orders and orchestrates calls to Inventory and Payment services
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Order Service received event:', JSON.stringify(event));
+
+  return withSpan('process-order', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, items, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !items || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, items, paymentMethod',
+        });
+      }
+
+      // Add order details to span
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'order.items.count': items.length,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing order ${orderId} for customer ${customerId}`);
+
+      // Step 1: Check inventory
+      console.log('Step 1: Checking inventory');
+      const inventoryUrl = process.env.INVENTORY_SERVICE_URL || 'http://localhost:3001/inventory';
+      
+      let inventoryResult;
+      try {
+        inventoryResult = await withSpan('check-inventory', async (inventorySpan) => {
+          addSpanAttributes({
+            'service': 'inventory',
+            'order.id': orderId,
+          });
+          
+          const result = await callService(inventoryUrl, {
+            orderId,
+            items,
+          });
+          
+          addSpanAttributes({
+            'inventory.available': result.available,
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Inventory check failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Inventory check failed',
+          details: error.message,
+        });
+      }
+
+      if (!inventoryResult.available) {
+        addSpanAttributes({
+          'inventory.status': 'out-of-stock',
+          'inventory.unavailable_items': JSON.stringify(inventoryResult.unavailableItems || []),
+        });
+        
+        console.log(`Order ${orderId} failed: Items out of stock`);
+        return createResponse(409, {
+          success: false,
+          orderId,
+          error: 'Items out of stock',
+          unavailableItems: inventoryResult.unavailableItems,
+        });
+      }
+
+      addSpanAttributes({ 'inventory.status': 'available' });
+
+      // Step 2: Process payment
+      console.log('Step 2: Processing payment');
+      const paymentUrl = process.env.PAYMENT_SERVICE_URL || 'http://localhost:3002/payment';
+      
+      let paymentResult;
+      try {
+        paymentResult = await withSpan('process-payment', async (paymentSpan) => {
+          const totalAmount = items.reduce((sum, item) => sum + (item.price * item.quantity), 0);
+          
+          addSpanAttributes({
+            'service': 'payment',
+            'order.id': orderId,
+            'payment.method': paymentMethod,
+            'payment.amount': totalAmount,
+          });
+          
+          const result = await callService(paymentUrl, {
+            orderId,
+            customerId,
+            amount: totalAmount,
+            paymentMethod,
+          });
+          
+          addSpanAttributes({
+            'payment.success': result.success,
+            'payment.transaction_id': result.transactionId || 'none',
+          });
+          
+          return result;
+        });
+      } catch (error) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Payment processing failed',
+        });
+        return createResponse(500, {
+          success: false,
+          orderId,
+          error: 'Payment processing failed',
+          details: error.message,
+        });
+      }
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.status': 'failed',
+          'payment.failure_reason': paymentResult.reason || 'unknown',
+        });
+        
+        console.log(`Order ${orderId} failed: Payment failed`);
+        return createResponse(402, {
+          success: false,
+          orderId,
+          error: 'Payment failed',
+          reason: paymentResult.reason,
+        });
+      }
+
+      addSpanAttributes({
+        'payment.status': 'success',
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      // Order successful
+      console.log(`Order ${orderId} completed successfully`);
+      
+      return createResponse(200, {
+        success: true,
+        orderId,
+        message: 'Order processed successfully',
+        transactionId: paymentResult.transactionId,
+        totalAmount: items.reduce((sum, item) => sum + (item.price * item.quantity), 0),
+      });
+
+    } catch (error) {
+      console.error('Order processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/src/payment-service/index.js b/src/payment-service/index.js
new file mode 100644
index 0000000..6a88ea6
--- /dev/null
+++ b/src/payment-service/index.js
@@ -0,0 +1,144 @@
+const { withSpan, addSpanAttributes } = require('../shared/tracer');
+const { createResponse } = require('../shared/utils');
+
+// Mock payment processing
+const FAILURE_PATTERNS = {
+  'card-declined': ['4111111111111111', 'card-declined'],
+  'insufficient-funds': ['4222222222222222', 'insufficient-funds'],
+  'expired-card': ['4333333333333333', 'expired-card'],
+};
+
+/**
+ * Simulate payment processing with some failure scenarios
+ * @param {string} paymentMethod - Payment method identifier
+ * @param {number} amount - Payment amount
+ * @returns {Object} Payment result
+ */
+function processPayment(paymentMethod, amount) {
+  // Check for known failure patterns
+  for (const [reason, patterns] of Object.entries(FAILURE_PATTERNS)) {
+    if (patterns.some(pattern => paymentMethod.includes(pattern))) {
+      return {
+        success: false,
+        reason: reason.replace('-', ' '),
+        transactionId: null,
+      };
+    }
+  }
+
+  // Simulate random failures (10% chance)
+  if (Math.random() < 0.1) {
+    const reasons = ['network-timeout', 'gateway-error', 'rate-limit-exceeded'];
+    const randomReason = reasons[Math.floor(Math.random() * reasons.length)];
+    return {
+      success: false,
+      reason: randomReason.replace('-', ' '),
+      transactionId: null,
+    };
+  }
+
+  // Successful payment
+  return {
+    success: true,
+    transactionId: `txn-${Date.now()}-${Math.random().toString(36).substring(2, 11)}`,
+  };
+}
+
+/**
+ * Payment Service Lambda Handler
+ * This service processes payments with failure scenarios for testing
+ * OpenTelemetry instrumentation is automatically provided by the Lambda Layer
+ */
+exports.handler = async (event) => {
+  console.log('Payment Service received event:', JSON.stringify(event));
+
+  return withSpan('process-payment', async (span) => {
+    try {
+      // Parse request body
+      const body = typeof event.body === 'string' ? JSON.parse(event.body) : event.body;
+      const { orderId, customerId, amount, paymentMethod } = body;
+
+      // Validate input
+      if (!orderId || !customerId || !amount || !paymentMethod) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Missing required fields',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Missing required fields: orderId, customerId, amount, paymentMethod',
+        });
+      }
+
+      addSpanAttributes({
+        'order.id': orderId,
+        'customer.id': customerId,
+        'payment.amount': amount,
+        'payment.method': paymentMethod,
+      });
+
+      console.log(`Processing payment for order ${orderId}, amount: ${amount}`);
+
+      // Validate amount
+      if (amount <= 0) {
+        addSpanAttributes({
+          'error': true,
+          'error.message': 'Invalid payment amount',
+        });
+        return createResponse(400, {
+          success: false,
+          error: 'Invalid payment amount',
+        });
+      }
+
+      // Process payment
+      const paymentResult = processPayment(paymentMethod, amount);
+
+      addSpanAttributes({
+        'payment.success': paymentResult.success,
+      });
+
+      if (!paymentResult.success) {
+        addSpanAttributes({
+          'payment.failure_reason': paymentResult.reason,
+        });
+        
+        console.log(`Payment failed for order ${orderId}: ${paymentResult.reason}`);
+        
+        return createResponse(200, {
+          success: false,
+          orderId,
+          reason: paymentResult.reason,
+          message: 'Payment processing failed',
+        });
+      }
+
+      addSpanAttributes({
+        'payment.transaction_id': paymentResult.transactionId,
+      });
+
+      console.log(`Payment successful for order ${orderId}. Transaction ID: ${paymentResult.transactionId}`);
+
+      return createResponse(200, {
+        success: true,
+        orderId,
+        transactionId: paymentResult.transactionId,
+        amount,
+        message: 'Payment processed successfully',
+      });
+
+    } catch (error) {
+      console.error('Payment processing error:', error);
+      addSpanAttributes({
+        'error': true,
+        'error.message': error.message,
+      });
+      
+      return createResponse(500, {
+        success: false,
+        error: 'Internal server error',
+        details: error.message,
+      });
+    }
+  });
+};
diff --git a/src/shared/tracer.js b/src/shared/tracer.js
new file mode 100644
index 0000000..3cedef5
--- /dev/null
+++ b/src/shared/tracer.js
@@ -0,0 +1,118 @@
+// When using OpenTelemetry Lambda Layer with auto-instrumentation,
+// the @opentelemetry/api is provided by the layer at /opt/nodejs/node_modules
+const api = require('@opentelemetry/api');
+
+/**
+ * Get the current active span
+ * The Lambda Layer automatically creates spans for Lambda invocations
+ * @returns {Span} Current active span
+ */
+function getCurrentSpan() {
+  return api.trace.getActiveSpan();
+}
+
+/**
+ * Get a tracer instance
+ * @param {string} name - Tracer name (usually service name)
+ * @param {string} version - Service version
+ * @returns {Tracer} OpenTelemetry tracer instance
+ */
+function getTracer(name = 'lambda-app', version = '1.0.0') {
+  return api.trace.getTracer(name, version);
+}
+
+/**
+ * Create a new span for a specific operation
+ * @param {string} spanName - Name of the span
+ * @param {Function} fn - Function to execute within the span
+ * @param {Object} attributes - Optional span attributes
+ * @returns {Promise} Result of the function execution
+ */
+async function withSpan(spanName, fn, attributes = {}) {
+  const tracer = getTracer();
+  return tracer.startActiveSpan(spanName, async (span) => {
+    try {
+      // Add custom attributes
+      Object.entries(attributes).forEach(([key, value]) => {
+        span.setAttribute(key, value);
+      });
+      
+      const result = await fn(span);
+      span.setStatus({ code: api.SpanStatusCode.OK });
+      return result;
+    } catch (error) {
+      span.setStatus({
+        code: api.SpanStatusCode.ERROR,
+        message: error.message,
+      });
+      span.recordException(error);
+      throw error;
+    } finally {
+      span.end();
+    }
+  });
+}
+
+/**
+ * Add custom attributes to the current span
+ * @param {Object} attributes - Key-value pairs of attributes to add
+ */
+function addSpanAttributes(attributes) {
+  const span = getCurrentSpan();
+  if (span) {
+    Object.entries(attributes).forEach(([key, value]) => {
+      if (value !== null && value !== undefined) {
+        span.setAttribute(key, value);
+      }
+    });
+  }
+}
+
+/**
+ * Record an exception on the current span
+ * @param {Error} error - Error to record
+ */
+function recordException(error) {
+  const span = getCurrentSpan();
+  if (span) {
+    span.recordException(error);
+    span.setStatus({
+      code: api.SpanStatusCode.ERROR,
+      message: error.message,
+    });
+  }
+}
+
+/**
+ * Inject trace context into headers for downstream service calls
+ * Uses W3C Trace Context propagation
+ * @returns {Object} Headers with trace context
+ */
+function injectTraceContext() {
+  const headers = {};
+  const span = getCurrentSpan();
+  
+  if (span) {
+    const spanContext = span.spanContext();
+    if (spanContext && spanContext.traceId && spanContext.spanId) {
+      // W3C Trace Context format
+      const traceFlags = spanContext.traceFlags || 0;
+      headers.traceparent = `00-${spanContext.traceId}-${spanContext.spanId}-${traceFlags.toString(16).padStart(2, '0')}`;
+      
+      if (spanContext.traceState) {
+        headers.tracestate = spanContext.traceState.serialize();
+      }
+    }
+  }
+  
+  return headers;
+}
+
+module.exports = {
+  getTracer,
+  getCurrentSpan,
+  withSpan,
+  addSpanAttributes,
+  recordException,
+  injectTraceContext,
+};
diff --git a/src/shared/utils.js b/src/shared/utils.js
new file mode 100644
index 0000000..2da73e3
--- /dev/null
+++ b/src/shared/utils.js
@@ -0,0 +1,61 @@
+const axios = require('axios');
+const { injectTraceContext } = require('./tracer');
+
+/**
+ * Make an HTTP request to another Lambda service with trace context propagation
+ * @param {string} url - Service URL
+ * @param {Object} data - Request payload
+ * @param {string} method - HTTP method (default: POST)
+ * @returns {Promise<Object>} Response data
+ */
+async function callService(url, data, method = 'POST') {
+  // Inject trace context into headers
+  const headers = {
+    'Content-Type': 'application/json',
+    ...injectTraceContext(),
+  };
+
+  console.log(`Calling service: ${url} with method: ${method}`);
+  console.log(`Trace context headers:`, headers);
+
+  try {
+    const response = await axios({
+      method,
+      url,
+      data,
+      headers,
+    });
+
+    console.log(`Service call successful: ${url}`);
+    return response.data;
+  } catch (error) {
+    console.error(`Service call failed: ${url}`, error.message);
+    if (error.response) {
+      throw new Error(`Service call failed: ${error.response.status} - ${JSON.stringify(error.response.data)}`);
+    }
+    throw error;
+  }
+}
+
+/**
+ * Create a Lambda response object
+ * @param {number} statusCode - HTTP status code
+ * @param {Object} body - Response body
+ * @param {Object} headers - Additional headers
+ * @returns {Object} Lambda response object
+ */
+function createResponse(statusCode, body, headers = {}) {
+  return {
+    statusCode,
+    headers: {
+      'Content-Type': 'application/json',
+      ...headers,
+    },
+    body: JSON.stringify(body),
+  };
+}
+
+module.exports = {
+  callService,
+  createResponse,
+};
diff --git a/template.yaml b/template.yaml
new file mode 100644
index 0000000..bc11944
--- /dev/null
+++ b/template.yaml
@@ -0,0 +1,137 @@
+AWSTemplateFormatVersion: '2010-09-09'
+Transform: AWS::Serverless-2016-10-31
+Description: Lambda OpenTelemetry Demo - Order, Inventory, and Payment Services with AWS ADOT Layer
+
+Globals:
+  Function:
+    Timeout: 30
+    MemorySize: 512
+    Runtime: nodejs20.x
+    Environment:
+      Variables:
+        AWS_LAMBDA_EXEC_WRAPPER: /opt/otel-handler
+        OTEL_SERVICE_NAME: will-be-overridden
+        OTEL_TRACES_SAMPLER: AlwaysOn
+        OTEL_EXPORTER_OTLP_PROTOCOL: http/protobuf
+        OTEL_EXPORTER_OTLP_ENDPOINT: !Ref OtelCollectorEndpoint
+        OTEL_PROPAGATORS: tracecontext
+        OTEL_RESOURCE_ATTRIBUTES: !Sub deployment.environment=${Environment}
+
+Parameters:
+  OtelCollectorEndpoint:
+    Type: String
+    Default: 'http://localhost:4318'
+    Description: OpenTelemetry Collector endpoint URL (without /v1/traces path)
+  
+  Environment:
+    Type: String
+    Default: 'production'
+    Description: Deployment environment (e.g., development, staging, production)
+  
+  AdotLayerArn:
+    Type: String
+    Default: 'arn:aws:lambda:us-east-1:901920570463:layer:aws-otel-nodejs-amd64-ver-1-18-1:5'
+    Description: |
+      ARN of the AWS Distro for OpenTelemetry (ADOT) Lambda Layer for Node.js.
+      Find the latest ARN for your region at:
+      https://aws-otel.github.io/docs/getting-started/lambda/lambda-js
+
+Resources:
+  # Order Service Function
+  OrderServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: order-service
+      CodeUri: ./
+      Handler: src/order-service/index.handler
+      Description: Order Service - Orchestrates order processing
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: order-service
+          INVENTORY_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+          PAYMENT_SERVICE_URL: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+      Events:
+        OrderApi:
+          Type: Api
+          Properties:
+            Path: /order
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Inventory Service Function
+  InventoryServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: inventory-service
+      CodeUri: ./
+      Handler: src/inventory-service/index.handler
+      Description: Inventory Service - Checks item availability
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: inventory-service
+      Events:
+        InventoryApi:
+          Type: Api
+          Properties:
+            Path: /inventory
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # Payment Service Function
+  PaymentServiceFunction:
+    Type: AWS::Serverless::Function
+    Metadata:
+      BuildMethod: nodejs20.x
+    Properties:
+      FunctionName: payment-service
+      CodeUri: ./
+      Handler: src/payment-service/index.handler
+      Description: Payment Service - Processes payments
+      Layers:
+        - !Ref AdotLayerArn
+      Environment:
+        Variables:
+          OTEL_SERVICE_NAME: payment-service
+      Events:
+        PaymentApi:
+          Type: Api
+          Properties:
+            Path: /payment
+            Method: post
+            RestApiId: !Ref ApiGateway
+
+  # API Gateway
+  ApiGateway:
+    Type: AWS::Serverless::Api
+    Properties:
+      StageName: Prod
+      Description: API Gateway for Lambda OpenTelemetry Demo
+
+Outputs:
+  ApiEndpoint:
+    Description: API Gateway endpoint URL
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod'
+  
+  OrderServiceUrl:
+    Description: Order Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/order'
+    
+  InventoryServiceUrl:
+    Description: Inventory Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/inventory'
+    
+  PaymentServiceUrl:
+    Description: Payment Service endpoint
+    Value: !Sub 'https://${ApiGateway}.execute-api.${AWS::Region}.amazonaws.com/Prod/payment'
+  
+  AdotLayerVersion:
+    Description: ADOT Lambda Layer ARN being used
+    Value: !Ref AdotLayerArn
diff --git a/test-api.sh b/test-api.sh
new file mode 100755
index 0000000..680b864
--- /dev/null
+++ b/test-api.sh
@@ -0,0 +1,130 @@
+#!/bin/bash
+
+# Color codes for output
+GREEN='\033[0;32m'
+BLUE='\033[0;34m'
+YELLOW='\033[1;33m'
+RED='\033[0;31m'
+NC='\033[0m' # No Color
+
+echo -e "${BLUE}========================================${NC}"
+echo -e "${BLUE}Lambda OpenTelemetry Demo - Test Script${NC}"
+echo -e "${BLUE}========================================${NC}"
+echo ""
+
+# Check if API endpoint is provided
+if [ -z "$1" ]; then
+    echo -e "${RED}Error: API endpoint is required${NC}"
+    echo "Usage: ./test-api.sh <API_ENDPOINT>"
+    echo "Example: ./test-api.sh https://abc123.execute-api.us-east-1.amazonaws.com/Prod"
+    exit 1
+fi
+
+API_ENDPOINT=$1
+ORDER_URL="${API_ENDPOINT}/order"
+
+echo -e "${YELLOW}Using API Endpoint: ${API_ENDPOINT}${NC}"
+echo ""
+
+# Test 1: Successful Order
+echo -e "${BLUE}Test 1: Successful Order${NC}"
+echo "Testing with items that are in stock and valid payment method..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 2: Out of Stock Order
+echo -e "${BLUE}Test 2: Out of Stock Order${NC}"
+echo "Testing with items that are out of stock..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 3: Payment Failure (Card Declined)
+echo -e "${BLUE}Test 3: Payment Failure - Card Declined${NC}"
+echo "Testing with a payment method that will be declined..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+sleep 2
+
+# Test 4: Payment Failure (Insufficient Funds)
+echo -e "${BLUE}Test 4: Payment Failure - Insufficient Funds${NC}"
+echo "Testing with insufficient funds scenario..."
+curl -X POST ${ORDER_URL} \
+  -H "Content-Type: application/json" \
+  -d '{
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }'
+echo -e "\n"
+
+echo -e "${GREEN}========================================${NC}"
+echo -e "${GREEN}All tests completed!${NC}"
+echo -e "${GREEN}Check your OpenTelemetry backend to view the traces${NC}"
+echo -e "${GREEN}========================================${NC}"
diff --git a/test-payloads.json b/test-payloads.json
new file mode 100644
index 0000000..603d30c
--- /dev/null
+++ b/test-payloads.json
@@ -0,0 +1,66 @@
+{
+  "successfulOrder": {
+    "orderId": "ORD-001",
+    "customerId": "CUST-123",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      },
+      {
+        "itemId": "item-002",
+        "name": "Mouse",
+        "quantity": 2,
+        "price": 29.99
+      }
+    ]
+  },
+  "outOfStockOrder": {
+    "orderId": "ORD-002",
+    "customerId": "CUST-456",
+    "paymentMethod": "credit-card-5555",
+    "items": [
+      {
+        "itemId": "item-003",
+        "name": "Keyboard",
+        "quantity": 1,
+        "price": 79.99
+      },
+      {
+        "itemId": "item-005",
+        "name": "Headphones",
+        "quantity": 1,
+        "price": 149.99
+      }
+    ]
+  },
+  "paymentFailureOrder": {
+    "orderId": "ORD-003",
+    "customerId": "CUST-789",
+    "paymentMethod": "4111111111111111",
+    "items": [
+      {
+        "itemId": "item-001",
+        "name": "Laptop",
+        "quantity": 1,
+        "price": 999.99
+      }
+    ]
+  },
+  "insufficientFundsOrder": {
+    "orderId": "ORD-004",
+    "customerId": "CUST-999",
+    "paymentMethod": "4222222222222222",
+    "items": [
+      {
+        "itemId": "item-004",
+        "name": "Monitor",
+        "quantity": 2,
+        "price": 399.99
+      }
+    ]
+  }
+}