Full-Stack AI Developer

We need to build an MVP conversational AI chatbot with the following components: Backend • Integration with Anthropic Claude API (preferred) or OpenAI GPT-4o • RAG (retrieval-augmented generation) pipeline using LlamaIndex or LangChain • Vector storage and backend logic consolidated on a unified platform (Supabase pgvector or equivalent) — avoid custom Express/FastAPI backends unless there is a compelling reason • System prompt engineering to enforce a specific persona, value set, and response boundaries Frontend • Clean, minimal chat interface built in React or Next.js (Vercel AI SDK preferred) • No user authentication required at MVP stage • Mobile-responsive design Hosting • Deployment to Vercel (frontend) with backend consolidated on the same unified platform where possible • Must be stable and fully documented for handoff