It was 6 AM when the first alert fired. Then the second. Then the third.The on-call engineer opened her laptop to find 3 unrelated failures from a single AI agent. The agent handled support tickets, processed billing adjustments, and answered customer questions. It ran on LangChain. It had passed every test in staging, and it worked—until it didn't.I've watched teams pour months into prompt engineering and model selection only to lose a weekend cleaning up an incident that had nothing to do with either. The failures that follow are not hypothetical. They're the kind of thing that happens the