How do you perform parallel test execution?

Short answer: Use built-in test runner features in frameworks like xUnit or NUnit to enable parallelization. Configure CollectionBehavior or run tests in separate processes/threads, ensuring tests are independent and stateless.

Real-world example (ShopNest)

ShopNest unit tests cover pricing and discount rules so a bad coupon change fails in CI before customers see it.

Say this in the interview

1. Define — one clear sentence (the short answer above).
2. Example — relate it to a project like ShopNest or your real work.
3. Trade-off — when you would not use it.