Scala was our primary candidate, but there were issues back then, namely in terms of compiler performance and also tooling. Tooling isn't easy for Scala, and I

Scala was our primary candidate, but there were issues back then, namely in terms of compiler performance and also tooling. Tooling isn't easy for Scala, and I believe compiler speed, Kotlin is already faster than Scala in terms. Also, we want to continue to provide support for JDK 6 thru 8.