Do this within a day of the session. Your workbook has space for all of it — these questions are here so you can see them without opening the file.

What you noticed

• Which policy was easiest to verify independently?
• When did verification become ambiguous?
• Which behaviors started to overlap?
• What setup would make a test feel expensive?

Going a little deeper

• Which requirement first made the design hard to reason about?
• Which test exposed a missing boundary?
• Where did AI help you see a simpler shape?
• Where did AI preserve or increase the tangle?
• What changed when you asked for independent verification instead of implementation?

What we named

Three virtues came out of the work rather than being handed to you at the start:

• Simple — one twist. One idea you can understand without untangling another.
• Composable — pieces that combine without tangling the rules together.
• Testable — behavior that can be verified on its own.

These are the same instincts behind the CLEAN code qualities in Beyond Legacy Code — and they are worth more now than they have ever been, because the cost of producing code has collapsed while the cost of understanding it has not.

And the quieter idea underneath all of it: assertions are mirrors. They reveal what we believe the system should mean.

Share one thing

Add a comment on this lesson:

Name one test you have written or inherited that was trying to verify too many things — and what you think the design was trying to tell you.

It takes real discipline to stay at the level of behavior when you could just ask for the code instead. That restraint is the skill, and this Studio asks a lot of it.