Python AI Developer for AI Chatbot (ChatGPT or Claude)

My product is a web application that helps social media managers see how their accounts perform. It pulls data from social media via API, passes it to an analytics layer, and shows the results on a customer dashboard. The data side is working, and now I need a Python developer experienced in software development and AI development to build a custom AI chatbot that plugs into it. The chatbot should let a manager ask a question in plain language, let's say "Which posts drove the most engagement last month?" or "Why did reach drop on one account?" and get a clear answer based only on that customer's own data. It will use a large language model through an API such as the OpenAI API or Claude API, and I expect retrieval augmented generation (RAG) with a vector database so answers come from real numbers and not from guesses. Prompt engineering, conversation memory and strict data isolation between tenants are part of the job. Background in AI chatbot development, conversational AI, LLM API integration is a must. On the technical side, the service is built in Python and runs in Docker, and PostgreSQL stores the data. I am open to Django or FastAPI, and to LangChain if you find it useful. Expect SQL queries against the analytics tables, some data preparation in pandas, and a REST API that connects the chatbot to the dashboard. The chat window is built with React and JavaScript, so you need to be comfortable agreeing on the API contract with the front end. In your proposal, please share a chatbot or LLM project you built, explain your plan for keeping answers grounded in customer data, and name the stack you would pick for this one and why.