Kotlin does have interop with Java, but is limited by either the features not existing in Java (non-nullable types) or behave differently in Java (records, etc.

Kotlin does have interop with Java, but is limited by either the features not existing in Java (non-nullable types) or behave differently in Java (records, etc.). You have to explicitly annotate that a Kotlin data class is a Java record due to the limitations Java has on records compared to data classes [1]. This is similar to adding nullable/not-null annotations in Java that are mapped to Kotlin's nullable/non-nullable types. Where there is a clean 1-1 mapping and you are targeting the appropriate version of Java, the Kotlin compiler will emit the appropriate Java bytecode. [1] https://kotlinlang.org/docs/jvm-records.html#declare-records-in-kotlin https://kotlinlang.org/docs/jvm-records.html#declare-records...