Rehan M.

Senior full stack engineer ( 11+ years ): 100% Job Success across 83 Upwork contracts. I ship and maintain production Ruby on Rails and Python systems, and I build LLM features that hold up in production: Anthropic/Claude API, RAG pipelines, pgvector, MCP tool-calling. Three things I do best: Ruby on Rails : SaaS modernization, major-version upgrades, Sidekiq, RSpec, performance and production reliability on AWS/Heroku. Python backend & data : FastAPI and Django services on PostgreSQL, including a data platform processing 500K+ transactions per month. AI/LLM integration : a Claude + pgvector workflow I built cut manual triage by 40%. My rule: deterministic code makes the decisions, the LLM writes the explanations. That's why my AI features don't break in production. Also in the toolbox: React, Next.js, TypeScript, Node.js, Stripe (webhooks, idempotency, reconciliation), Docker, Kubernetes, Redis. Past clients include TMobile, Toyota North America, edX, Kayak, Insurify, and Kyruus. Based in Dallas, TX (Central Time) : Full US business hours overlap and clear written communication. And honest scoping: if part of your project sits outside my experience, I'll say so up front and tell you exactly how I'd close the gap. Tell me what's breaking or what you're trying to ship, and I'll reply with how I'd approach your specific situation - not a template.