Seconding the sibling comment re: Kotlin. I haven't worked much with it personally, but I've heard from plenty of people that it strikes a good balance between

Seconding the sibling comment re: Kotlin. I haven't worked much with it personally, but I've heard from plenty of people that it strikes a good balance between Java being... Java and Scala's floundering. Rust also checks your feature boxes, but staying in the JVM-verse is almost certainly the safer bet unless you end up really needing fast native binaries that aren't a chore to code.