I think you can find koans for a lot of languages (mostly pre written tests, where you write code to make those tests pass. Some examples: 1. Kotlin Koans (htt

I think you can find koans for a lot of languages (mostly pre written tests, where you write code to make those tests pass. Some examples: 1. Kotlin Koans (https://play.kotlinlang.org/koans/overview https://play.kotlinlang.org/koans/overview) 2. Ruby koans (http://rubykoans.com/ http://rubykoans.com/)