The fact that it didn't even make the list should give you a clue that Kotlin is not a particularly relevant language outside Android apps, where it's poised to become important.

Who knows, maybe in 5 years it will make the list.

And swift is very popular on server side ? On an overall basis, here's Github's official stats - check the growth of Kotlin vs Swift : https://github.blog/2018-11-15-state-of-the-octoverse-top-pr...

Here's my claim - Kotlin simply BLOWS AWAY Swift when it comes to server side

https://engineering.khanacademy.org/posts/kotlin-adoption.ht...

https://medium.com/insiden26/5-reasons-why-n26-is-moving-to-...

https://devcenter.heroku.com/articles/getting-started-with-k...

https://twitter.com/yogurtearl/status/1012551386536394753

https://medium.com/@napperley/kotlin-server-side-adoption-d1...

https://blog.jetbrains.com/kotlin/2018/11/ktor-1-0/

https://pusher.com/state-of-kotlin

It might turn out, given IBM's support.

Kotlin is pretty much a thing on Android, and only because Google doesn't bother to support anything beyond Java 8.

Outside Android we get to enjoy Java's improvements.