Suppose you’re working on a project which is running on Kubernetes - like we usually do - and you would like to test out this project on each and every pull request or commit. You can write many unit and integration tests, but at the end of the day, the proof of the pudding is in the eating. A real test would be to start up the application on the same platform where it will end up being deployed in production (in this case Kubernetes) and exercise it with some real workloads (aka end-to-end tests).