Nolan Lawson names the failure mode of AI code review: epicycles

Lawson argues that agentic code review has made bug-finding nearly free while human tolerance for bugs hasn't moved: "you can basically find as many bugs as you ask the agents for." Left unmanaged, he says that produces epicycles, the term for the extra circles ancient astronomers kept adding to a wrong model of the solar system to make it fit new observations. Agents are good at patching an individual bug and bad at the "dramatic simplification" that would remove a whole class of bugs at once: "They will happily build one epicycle per bug until the code is a spaghetti mess." His counter-measures: ask the agent how to simplify the design during review, not only how to fix the bug in front of it; lean on exhaustive test suites so an agent can grind toward a near-100% pass rate, as he found while rebuilding the W3C IndexedDB API against its test suite; and favor architectures, multi-page apps over single-page apps in his example, that make whole bug categories, like a broken back button or lost scroll state, structurally impossible rather than something to patch one at a time.

Why it matters: "epicycles" is a useful name for a pattern teams doing heavy AI code review will likely recognize once it's pointed out, and Lawson's fix is a review habit, not a new tool: ask for the simplification before you ask for the patch.