LLM API calls fail between 1% and 5% of the time in production. Not from hallucinations. From 429 errors nobody handled. You've probably seen this: you ship an agent, everything works in staging, prod hits a burst of traffic, the provider throttles you, and suddenly your agent is retrying forever, burning tokens on every attempt, and the cost graph spikes sideways. The incident isn't model quality. It's the retry loop you forgot to fence. I've written about production architecture for ag...