Insights
Engineering notes from systems where the enemy is a wrong number that looks right. Everything here comes from shipped work; nothing is hypothetical.
A model returned 52 of 54 rows and every plausibility check passed. Why statistical checks structurally cannot catch silent data loss — and why the fix was a set difference, not a better prompt.
The high-risk obligations apply since 2 August 2026. An engineer’s reading: record-keeping, traceability, human oversight and accuracy are architecture properties — and five questions that tell you where you stand.
The same system validates some model outputs with forced schemas and others with a shrug — and that’s correct. A taxonomy for matching validation contracts to blast radius.
The most underrated feature in a regulated system is a clean no. A pre-flight rejection is a support ticket; an approximate answer is an assessment — for tax engines and AI agents alike.