[ptx]

Kotlin is really very similar to C#. Java developers shouldn't have much of a problem either (now that Java finally has lambdas), and I hear Scala is mostly a superset of Kotlin.

GraphQL and (Kotlin or C# or Java or Scala) probably isn't that small of a niche.

Edit: Also, Kotlin does have near total compatibility with Java and can use any Java library (aside from the most magical bytecode-rewriting annotation processors) so I don't understand what you're saying about having to rewrite things that exist.

[erik_seaberg]

I'd put it the other way around, Kotlin is a subset of Scala that the masses might be ready for. I would always prefer the kind of candidate who's excited about stuff like Kotlin over others.