Senior Python backend engineer for hire. I make AI-era and money-critical code production-safe.
Payments, MCP servers, and AI features that hold up under load, replay, and attack, well past the happy-path demo. Every repo below is inspectable: tests, CI, and a benchmark or exploit walkthrough that backs the claim.
YAML-driven governance and audit reverse-proxy for MCP. Every request runs the full pipeline: authenticate principal, verify HMAC signature, RBAC/tenant policy, per-tenant rate limit, route to the tenant's upstream, PII-redact the result, audit. Tenant isolation is structural (separate upstreams, credentials, and state per tenant) and the whole thing is dependency-light and offline-testable.
Before/after security hardening of an AI-generated SaaS. 19 findings (5 critical, 8 high, 4 medium, 2 low), each with an exploit walkthrough and a proving test. The exploit tests pass on the before branch (21 tests, demonstrating each hole) and flip green on main (52 tests, asserting closure). The diff is the pitch.
Test-mode SaaS billing where double-charging is structurally impossible: a single-writer webhook projection plus a DB-enforced one-charge-per-invoice guard. The chaos harness fires duplicate, out-of-order, dropped-then-redelivered, and shuffled multi-customer webhook batches at the live app: 5 scenarios, 45 deliveries, 0 double charges.
Benchmarked invoice/document extraction: PII redaction before any model call, field-level confidence scoring, a confidence-gated human review queue, and a correction-feedback loop. Macro-F1 0.902 vs 0.221 for the naive single-prompt baseline (synthetic dataset, mock backend, clearly labeled; the real-dataset/real-model run is a documented next step).
Production-shaped QuickBooks Online MCP server. Full OAuth 2.1 authorization-code + PKCE flow, automatic token refresh, dual token-bucket rate limiting honoring QBO throttles, Retry-After-aware backoff, SyncToken enforcement on writes, and structured error mapping. 18 tools plus 3 read-only resources, 55 offline tests.
A static misconfiguration scanner for AI-generated apps, a HubSpot MCP server, a drop-in idempotent Stripe webhook handler, a zero-downtime billing-migration runbook with a parity harness, and AI-feature retrofits on real stacks. Browse the pinned repos.
Portfolio and contact → · amin.ale.business@gmail.com
Sole proprietor, invoice-only. Available for MCP integrations, payment and billing systems, security hardening of AI-generated apps, and production-grade AI features.