Senior Full-Stack Developer for AI-Powered SaaS Platform (React, Node.js, LangChain)

We are building an AI-powered SaaS platform and looking for a senior full-stack developer to join as a long-term technical partner. The initial engagement is a paid technical assessment: a focused task (4-8 hours) to evaluate fit before we move into the full project. If it goes well, we extend into ongoing work. The platform involves: — React / Next.js frontend with real-time features — Node.js / GraphQL backend — LLM integration (OpenAI / Anthropic) — RAG pipeline with vector database (Pinecone or pgvector) — AWS or GCP deployment What we are looking for: — Strong hands-on experience with React, TypeScript, and Node.js — Experience integrating LLMs into production applications — Familiarity with LangChain or similar frameworks is a strong plus — Clean code, good communication, no hand-holding needed To apply, please share: 1. One relevant project you have built — what it did and what you were responsible for 2. Your experience with LLM integration specifically 3. Your availability and preferred hourly rate