How I Built an AI-Powered Trading Platform Solo in 30 Days (FastAPI + React + Rust + OpenRouter)

How I Built an AI-Powered Trading Platform Solo in 30 Days (FastAPI + React + Rust + OpenRouter) I built Chai Street — an AI-powered trading intelligence platform — solo, in one month. Nights and weekends. 6-12 hours a day. Eyes hurting, leg muscles gone, cortisol through the roof. But the pain was sweet. This is the full technical breakdown — every major decision, what worked, what didn't, and what I'd do differently. The stack at a glance Frontend → React 19 + Vite + Tailwind CSS (Vercel) Backend → FastAPI + Uvicorn + SQLite (Railway) Scanners → Python (LEAP) + Node.js + Rust binary (CSP) LLM → OpenRouter (Claude/GPT/Gemini via one API key) Auth → JWT HS256 + PBKDF2-SHA256 password hashing Billing → Stripe Email → Resend 13 external providers. One developer. Why FastAPI over Django or Flask Django is too opinionated for a data-heavy API — I don't need its ORM, admin panel, or template engine. Flask is too bare-bones; I'd be rebuilding request validation from scratch. FastAPI hits the