One popular way of testing in the Scala community is property-based testing — by generating random, often unexpected test data, it can uncover shortcomings in our implementations. In this talk, you will learn about a completely different approach, mutation testing: By mutating your code, it tests your tests and tells you a lot more about the quality of your tests than metrics like code coverage. We’re going to cover what mutation testing us, how you can use it in your Scala projects, how it compares to property-based testing, and the challenges of implementing this approach in Scala.