Kotlin is a good improvement over Java 8 for three reasons, in my view. Less verbose: Not everything has to be in a class. Structural typing: val/var a = 5; Ex

Kotlin is a good improvement over Java 8 for three reasons, in my view. Less verbose: Not everything has to be in a class. Structural typing: val/var a = 5; Explicit null: String? can be null, String can't. It also helps that Kotlin has a decent JavaScript compiler (and thus can share code between backend/frontend). The compiler is fast (unlike Scala) and it's still a simpler language than Scala.