Building an AI Customer Support Chatbot from Scratch
A step-by-step walkthrough of designing a production-grade support agent — from intent modeling and retrieval design to tool orchestration, guardrails, and evaluation.
Most 'AI chatbot' tutorials stop at a prompt and a chat window. This post picks up where those leave off: how to design a support agent that survives contact with real users, real tickets, and real edge cases.
We start with the boring but critical work — mapping the conversation space, defining tools with clear contracts, and deciding what the agent is explicitly not allowed to do. Then we layer retrieval-augmented generation on top of a curated knowledge base, using hybrid search and re-ranking to keep answers grounded.
Finally, we wire in evaluation. Every deployed agent needs an eval harness: a set of scenarios that run on every change, scoring correctness, tone, and escalation behavior. Without it, you're shipping vibes. With it, you can iterate confidently and catch regressions before customers do.
DevSpark
AI & Backend Engineer