Hello everyone!
We have developed a new way of end-to-end testing your 
back-end Kotlin APIs.
Especially if you’re using 
Spring-Boot with Kotlin, or Ktor, it provides a robust API to assert your application’s and physical components’ state.
Physical components as in 
Kafka, Couchbase, MongoDb, External API calls, etc… You have full control over assertions of these components.
It is very useful for most use cases and is extensible.
You can read the medium post.
We have also open-sourced it; you can find it here: 
https://github.com/Trendyol/stove4k
I hope you find it useful, too. Please share if you would have any feedback.
Cheers.