<objective A suite with 4,000 tests where 800 are disabled and 200 are flaky looks healthy on a slide and lies in production. This skill defines the metrics that actually change behavior — each one with a formula, a target, an owner, and a concrete action when it goes red — so the dashboard becomes a feedback loop instead of decoration. </objective Quick Route | Your situation | Metric to reach for | Section / reference | |---|---|---| | No metrics yet, where to start | code coverage, flakiness, defect escape | Core Principles + | | Bugs escaping despite high coverage | defect escape rate + m…