A modern programming language that makes developers happier.

kotlinlang

yes, and we're all always learning, and always bringing on new people to our teams that will have to learn it. Kotlin was designed by JetBrains to be used to write a huge Java program with a billion moving parts, and I'm sure they have engineers joining and leaving constantly. A Scala codebase isn't open to "Java developers" the way a Kotlin codebase is. Sure, you both know Scala very well, but if you use it in your jobs, you'll be limiting the pool of people you can work with. Lots of people are not going to be as willing as you to put in the time to learn such a complex language