What is MSTest and when should you use it?

Short answer: MSTest is Microsoft's official unit testing framework for .NET. It’s tightly integrated with Visual Studio and is a good choice for teams using Microsoft tooling and wanting a straightforward, supported testing solution without external dependencies.

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.