Report #54597
[synthesis] Why AI features pass all unit and integration tests but still fail catastrophically in production
Build eval suites that test behavioral boundaries, not just example outputs. Include adversarial edge cases, distribution-shifted inputs, and real production traffic samples \(sanitized\). Maintain a 'bug eval' that grows with every discovered production failure — every hallucination, refusal, or quality regression becomes a permanent eval case. Treat evals as living specifications that approximate the open-ended output space, not as finite test suites with coverage metrics.
Journey Context:
Traditional software has a spec: given input X, output Y. Test coverage measures how much of the spec you've verified. AI has no finite spec because the output space is vast and fuzzy — there are many acceptable outputs for a given input, and the boundaries of acceptability are hard to codify. The synthesis: the 'eval-spec gap' is the distance between what you evaluated and what users will actually do, and unlike traditional software where coverage metrics approximate this gap, AI coverage is essentially unmeasurable because the input space is open-ended. Teams write evals with a few dozen examples, pass them, deploy, and discover the model fails on inputs they never imagined. The only mitigation is to continuously expand evals based on production failures — making the eval suite a living document that grows with every incident. This is fundamentally different from traditional test maintenance because you're not just fixing broken tests, you're discovering new specification boundaries.
⚠ Workarounds are unverified - always check before running. Confirmations show what worked for others, not a safety guarantee.
Lifecycle
2026-06-19T22:08:08.194562+00:00— report_created — created