AWS Practice Test Application - 3-Tier Architecture

A secure 3-tier architecture implementation of the AWS practice test application with React frontend, Node.js/Express backend, and PostgreSQL database.

Architecture

• Client Tier: React frontend application
• Server Tier: Node.js/Express REST API with JWT authentication
• Database Tier: PostgreSQL with migrated test data

Features

• User authentication (registration/login)
• All existing practice modes: Random Practice, Mock Test, Practice Mode
• New Study Mode with progress tracking
• Mock Test result history
• Secure API with SQL injection and XSS prevention
• Cross-device progress continuity

Quick Start

Prerequisites

• Docker and Docker Compose
• Node.js 16+ (for local development)

Development Setup

1. Clone the repository and navigate to the project directory

2. Copy environment variables:

   cp .env.example .env

3. Start all services with Docker Compose:

   docker-compose up --build

4. Access the application:

   • Frontend: http://localhost:3000
   • Backend API: http://localhost:5000
   • Database: localhost:5432

Manual Setup (without Docker)

1. Set up PostgreSQL database:

   createdb aws_practice

2. Install server dependencies:

   cd server
   npm install
   npm run migrate
   npm run dev

3. Install client dependencies:

   cd client
   npm install
   npm start

Project Structure

├── client/                 # React frontend
├── server/                 # Node.js/Express backend
├── docker-compose.yml      # Docker orchestration
├── .env                    # Environment variables
└── README.md              # This file

API Endpoints

Authentication

• POST /api/auth/register - User registration
• POST /api/auth/login - User login
• POST /api/auth/refresh - Refresh JWT token

Tests

• GET /api/tests - Get all available tests
• GET /api/tests/:id/questions - Get questions for a test

Progress (Protected)

• POST /api/progress/study - Save Study Mode progress
• GET /api/progress/study/:testId - Get Study Mode progress
• POST /api/progress/mock-test - Save Mock Test results
• GET /api/progress/mock-tests - Get Mock Test history
• GET /api/progress/stats - Get user statistics

Development

Database Migrations

Run migrations:

cd server
npm run migrate

Reset database:

cd server
npm run migrate:reset

Environment Variables

See .env.example for all available configuration options.

Security Features

• bcrypt password hashing
• JWT token authentication
• SQL injection prevention via parameterized queries
• XSS attack prevention via input sanitization
• CORS configuration
• Rate limiting
• Input validation

Deployment

The application is designed for AWS deployment:

• Frontend: S3 + CloudFront
• Backend: EC2
• Database: RDS PostgreSQL

License

MIT