Flakiness — The Operational Disease That Kills Test Signal
A flaky test — same code, different verdicts — is worse than no test: it costs full price, delivers noise, and teaches the team that red means retry. Post 1 did the arithmetic (ten thousand 99.9%-reliable tests ≈ permanent red); this post is the operating system for the disease: detect flakes statistically, quarantine them mechanically, fix them by root-cause class, and prevent the re-infection that follows any one-time cleanup.
Flakiness managed as an operational disease: detected statistically into per-test flake scores, quarantined mechanically (out of the gate, loudly, with fix-or-delete SLAs), fixed by taxonomy — synchronization over sleeps, hermetic isolation, fakes at boundaries — with lint rules and burn-in preventing re-infection.