A flaky test teaches the team to ignore warnings.
Intermittent failures erode trust in the entire feedback system.
Interpretation
A flaky test imposes a small tax on every run and a large tax on attention. Once rerun becomes the normal response, a real regression can pass as noise. Treat flakiness as a reliability defect: quarantine only to unblock work, then assign and repair it visibly.
Practice
- Measure flaky failures instead of relying on anecdotes.
- Remove timing dependence and shared mutable state.
- Give quarantined tests an owner and deadline.
Anti-pattern
Adding automatic retries until the pipeline looks green.