If you want to venture back to the JVM, Kotlin offers a very good middle ground between Java and Scala.
IntelliJ (Jetbrains are the leaders behind Kotlin) has first class support for the language. Gradle will have support for Kotlin as it's DSL in it's next major iteration.
Despite some very loud people on the internet, it seems to have close to zero adoption, and JetBrains making big promises and then failing to deliver anything is not really helping them.