Last week we wrote about feeding terabytes of CI logs to an LLM. Most of the questions on Hacker News weren't about the logs. They were about the agent: which models, how they coordinate, and how much it all costs. Today we run Opus 4.6 and pay less than when we ran everything on Sonnet 4.0. The reason is mostly what Opus doesn't do: 80% of failures never reach it, and when they do, it never reads a log line. The architecture looks like this: Let a cheap agent decide if the expensive one is need...