Lesson 4: Seeing what the model did, and changing it safely
22 min read·13 Oct 2026
Module 13 · Lesson 4 · About 50 minutes · Needs: Module 8 Lesson 2 (the hand-built tracer), Module 10 Lesson 5 (the CI gate), Module 11 Lesson 4 (redaction); Lessons 1 and 3 of this module help
The situation
It is Monday 31 August 2026, week 14. Drafted replies go live for billing and sign-in tickets, behind a feature flag. Maya asks what happens when a draft goes wrong at 3 a.m. Joel wants spend each day. Tomasz forwards a provider email: a model is being shut down.
The running example is T-1001, Ana Duarte's duplicate charge of 288 USD: traced, watched, tested on a new model, and made reversible.