Build a customer-support agent over a fake product/SQL database: tool-calling, retrieval, and a control loop.

A live-coding round that tells apart engineers who have shipped agents from those who have only read about them. Interviewers want a genuine plan-act-observe loop, tools that query a real SQL database, guardrails that block the obvious failures, and a concrete evaluation plan, rather than one prompt masquerading as an agent.

Updated Sep 2026 · Grounded in real GenAI, LLM, and AI/ML engineering interview loops and written to a senior-engineer editorial bar.