The Exercises
One hands-on drill per commandment, run in Claude Code against a practice repository.
Drill 02 · Design before code
The newsroom digest
A working news backend and a one-line ticket: add a daily digest of unread notifications. The obvious implementation ships with green tests and misses the constraints that live in neighboring modules. The drill is whether your plan goes looking for them.
Calibration: eight of eight unwarned runs missed an average of three of seven constraints.
Drill 10 · Commit or it didn't happen
The quarterly report
A product-analytics repo, two past quarterly reports, and a bare ticket: produce the Q3 report. The numbers are the bait. The graded question is what survives in the tree after the chat closes.
Calibration: eight of eight runs produced a report; not one left a way to reproduce it.
The practice repository and the remaining drills are being prepared. Each runs in Claude Code from a clean checkout; bring nothing but the chapter's law.