Load tests model realistic traffic; stress tests locate limits; soak tests expose degradation. Security checks include dependency scanning, static analysis, secret scanning, and authorization tests.

How to apply it

Define workload, duration, data shape, and success criteria. Run destructive tests in isolated environments. PRs explain problem, risks, tests, rollout, and migrations; reviewers examine authorization, data handling, error paths, observability, and accessibility.

Worked example

Test reading and updating a resource from another tenant and assert no data or side effect leaks.

Common mistakes to avoid

Assuming a green scanner proves security or running destructive tests against customer data.

Practice task

Implement this concept in the capstone. Add one positive test, one negative or failure-path test, and a short note explaining the trade-off you chose.