AI agents have made writing code nearly free, but this has introduced a new, hidden cost. The most expensive bugs are now caused by what the agent didn't write—missing edge case handling, like ensuring a money transfer is atomic (succeeds or fails completely). Our current tools (tests, code review) are good at finding errors in existing code but bad at spotting what's absent. This shifts the bottleneck from writing code to the slow, manual process of expert human review, as engineers must meticu...