I know that Kotlin can be pretty useful when creating a DSL (Domain Specific Language), which is probably relevant in many DevOps use cases - an example for such a DSL would be
https://dev.to/jmfayard/github-actions-a-new-hope-in-yaml-wasteland-1i9c by
@jmfayard -> let’s you write Kotlin instead of yaml for Github Actions. Might be also a good starting point for learning Kotlin 😉