One of Kotlin's design goals was 100% compatibility with java. Whenever I work on a java-codebase and see a class that could be expressed much simpler in Kotli

One of Kotlin's design goals was 100% compatibility with java. Whenever I work on a java-codebase and see a class that could be expressed much simpler in Kotlin I press "Cmd+Option+Shift+K". Intellij IDEA automatically converts this file to Kotlin. The codebase continues to work without issues and I can proceed extending this part in Kotlin.