Code Drift Wasn't New—AI Just Made It Impossible to Ignore

As AI coding agents scale up, they expose an old problem in new ways: misalignments between code, tests, documentation, and runtime behavior that traditional testing misses. This forces a fundamental shift from asking 'does the code work?' to 'is the system coherent?'. Understanding code quality now requires deterministic diagnostics across all repository layers, not just validating individual code changes.