Full-Stack AI Engineer - SaaS

Full-Stack AI Engineer (Contract, 4–6 Weeks) — Build (multi-LLM SaaS)

About the project
multi -llm AI chat app with smart model orchestration across OpenAI, Anthropic, Groq, Perplexity, OpenRouter, Together, Cohere, plus Azure OpenAI and AWS Bedrock. Features include safety checks, fallback routing, rate limits, and (Tap) payments.

Good news: We already have strong starter codebases and docs (generated via ChatGPT):

AI orchestration monorepo (Node + Python): Fastify SSE gateway, FastAPI router, 10+ provider adapters, safety (Azure Content Safety + PII redaction), Next.js chat UI, eval harness.

Backend starter (Spring Boot or Node alt): payments (Tap), subscriptions, /usage/report.

What you’ll deliver (MVP in 4–6 weeks)

Streaming chat: Stable SSE from gateway ? UI; retries + fallback routing using router alternatives.

Providers: OpenAI + Anthropic + 2–3 more (e.g., Groq, Perplexity, Cohere, Azure, Bedrock) working end-to-end.

Safety: Azure Content Safety pre-check + optional PII redaction.

Payments (Tap): Hosted checkout + webhook to activate subscription (Stripe optional later).

Usage metering: Post usage from gateway ? backend /usage/report; daily summary.

Deploy: Vercel (web), Render/Railway (gateway & router), Neon/Railway (Postgres).

Docs: README/runbook, .env samples, and Postman collection.

Milestones

Week 1: Deploy router, gateway, web; OpenAI/Anthropic streaming live.

Week 2: Add fallback, rate limit, basic usage post; integrate 1 extra provider.

Week 3: Tap hosted checkout + webhook; add 1–2 more providers; safety on.

Week 4–6: Eval harness + tuning, admin usage view, hardening, handover.

Tech you should know

Node/TypeScript (Fastify), Python (FastAPI), Next.js (SSE)

LLM provider APIs (OpenAI/Anthropic at minimum), streaming/SSE parsing

Basic DB & REST (Postgres, JSON endpoints)

Nice-to-have: Java/Spring Boot or Node billing, Azure OpenAI / Bedrock, Tap/Stripe, Docker, CI

Engagement: Contract (full-time or heavy part-time) for 4–6 weeks...then could be extendable further