Test it. Break it. Understand it.
Build confidence through concrete hypotheses, edge cases and checks that earn their place.
66 minutes4 lessons
What you’ll be able to do
Diagnose a save failure and prove a focused fix.
0 of 4 lessons complete
- 116 min
Tests are executable claims
Write checks around behavior that matters.
- 218 min
Debug with a hypothesis
Move from symptom to discriminating evidence.
- 317 min
Pure logic, messy boundaries
Keep deterministic decisions separate from clocks, networks and storage.
- 415 min
The unhappy path is a feature
Design for invalid input, repeated actions and unavailable services.