We eventually migrated the vast majority of our Scala code over to Kotlin (and a bit of PySpark). I found Kotlin to be great for writing very performant concur

We eventually migrated the vast majority of our Scala code over to Kotlin (and a bit of PySpark). I found Kotlin to be great for writing very performant concurrent code. It was actually easier to write faster code in Kotlin, and even though the pattern matching isn't quite as powerful, it was good enough. The code was also much easier to grok.