Lesson 4: Change one thing, log it, and know when to stop

Module 4 · Lesson 4 · About 55 minutes · Needs: Lesson 2 (the frozen split, the control prompt, run_prompt and score); Lesson 1 helps (prompts as files with an id)

The situation

It is Thursday 25 June 2026, week 4. Lena flags T-1004: Yuki Sato wants her money back for an annual plan she no longer uses. The gold label is cancellation, and triage keeps getting it wrong.

The quick fix is a sentence for it, plus a persona and a "take a deep breath" you saw online. Maya asks: "If the score moves, which of those three moved it?" This lesson follows T-1004's one-sentence rule through a disciplined change, and through the habits that quietly break prompts.