How long does it take to add AI to an existing MERN application?

Discovery and proof of concept takes two to three weeks. A production RAG chatbot on an existing MERN codebase takes eight to twelve weeks including data preparation, embedding pipeline, evaluation suite, guardrails, and observability. A full agentic system with tool use and human-in-the-loop takes sixteen to twenty-four weeks. Timelines assume weekly product reviews and a dedicated stakeholder on your side.