How do you handle versioning and compatibility in tests?

Short answer: Maintain backward-compatible tests for shared components, use feature flags to isolate new behaviors, update tests alongside code changes, and maintain multiple test branches if necessary.

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.