Being able to run a Ktor Server Instance embedded is absolutely delightful for writing integration tests betwen Client and Server. I can write tests that perform entire end-to-end User Registration/Activation/Login/Operation/Logout workflows. In the past developing such features has meant a lot of tedious environment wrangling as I build the server and client parts separately. Now the feedback loop is so tight, it's so much more enjoyable. Big love Ktor ❤️

Another neat thing about ktor is that you can spin up multiple servers listening on different ports in the same jvm instance. Very useful when prototyping new microservice based apps