How long to build a production MERN AI chatbot?

POC on your actual data: 3 to 4 weeks. Production customer support chatbot with RAG, streaming UI, guardrails, cost caps, evaluation suite, human handoff, and observability: 6 to 10 weeks. Enterprise multi-channel chatbot with agent handoff to your CRM or helpdesk, SSO, and role-based content access: 12 to 20 weeks. Timelines assume weekly product reviews with a dedicated stakeholder on your side, clean access to the source content the chatbot will answer from, and access to the internal APIs the chatbot will call (for agentic patterns).