We need ai developer for rag support with n8n Integration

We are lookingg for an experienced ai dev to build an MVP customer support assistant for our website. We currently have a collection of help articles, product documentation and internal faqs. We want the assistant to answer customer questions using this content, show relevant sources and escalate conversations when it cannot provide a reliable answer. The assistant should also collect lead details and send them to our CRM through n8n. We are open to recommendations on the best stack. We expect the solution will use Openai or Claude, Python, Fastapi, Langchain or Langgraph and a suitable Vector database.