How to Build Production-Grade AI Agents

Most AI agent demos look impressive for five minutes and painful in the long run. They can call a tool, stream a paragraph, maybe update a document, and then stop right where the real engineering work begins. Once you put an agent inside an actual product, you need much more than tool calling. You need resumable state, predictable execution, permission boundaries, observability, retries, approval flows, abort handling, model routing, and a UI that explains what the agent is doing without exposin