Why Smart Engineering Teams Rationally Ignore Flaky Tests — and Pay a Heavy Price

Flaky tests — those that fail intermittently without any code change — are a widespread problem even at top-tier tech companies, with Google reporting 84% of test transitions involving flakiness and Slack seeing over 56% of its mobile test failures as noise. Research shows developers spend an average of 30 minutes per flaky test investigation, and Atlassian estimated 150,000 developer hours lost annually before building dedicated detection tooling. The core problem is what engineers describe as 'rational inaction': every stakeholder in the chain — developer, QA engineer, infrastructure team, and manager — makes a locally sensible decision to defer or ignore the issue, yet the collective outcome is that nothing gets fixed. Because flakiness lacks a clear owner, a deadline, or visibility in the product backlog, it consistently loses out to user-facing priorities despite quietly accumulating into significant Test Debt. The result is that even technically strong, quality-conscious teams end up normalising test failures, eroding trust in their entire CI pipeline over time.