Full Stack AI Developer Needed to Build an AI-Powered SaaS Web App with Next.js, RAG and Supabase

We need an experienced Full Stack AI Developer to build a complete AI-powered SaaS web application from scratch. This is a single project with a defined scope and we are looking for someone who can own the entire build end to end. What we are building: An AI-powered SaaS platform that allows users to upload business documents, query them using natural language, and receive intelligent responses powered by a RAG (Retrieval-Augmented Generation) pipeline. The platform will include user authentication, subscription billing, a clean dashboard, and automation workflows connected to external tools. Project scope includes: Next.js and React frontend with Tailwind CSS — clean, responsive, production-ready UI Supabase backend with PostgreSQL database, user authentication, row-level security, and file storage RAG pipeline using pgvector or Pinecone — users upload PDFs and documents, the AI reasons over them Claude API or OpenAI API integration for the AI chat and document intelligence layer Stripe integration for subscription billing and payment management n8n automation workflows to handle notifications, data syncing, and third-party triggers Deployment to Vercel or Railway with environment configuration and basic documentation What we expect from you: You have built and shipped a RAG system or document intelligence tool before You are comfortable working independently and delivering clean, documented code You will provide progress updates and share a staging link before final delivery You have real Next.js and Supabase experience — not tutorial-level, production-level You can integrate Claude Code or OpenAI API properly with structured outputs and error handling Project timeline: We expect this to be completed within 3 to 6 weeks depending on your availability and approach. Please outline your proposed timeline in your proposal. To apply: Share at least one live project you have built that is similar in scope — a SaaS app, RAG system, or AI-powered web application. Tell us how you would approach this build and what your estimated timeline looks like. Generic copy-paste proposals will be ignored.