Kotlin is a programming language and has its own architecture to allocate memory and produce a quality output to the end user. Following are the different scenarios where Kotlin compiler will work differently, whenever it is targeting different other kind of languages such as Java and JavaScript.
Kotlin compiler creates a byte code and that byte code can run on the JVM, which is exactly equal to the byte code generated by the Java .class file. Whenever two byte coded file runs on the JVM, they can communicate with each other and this is how an interoperable feature is established in Kotlin for Java.
Whenever Kotlin targets JavaScript, the Kotlin compiler converts the .kt file into ES5.1 and generates a compatible code for JavaScript. Kotlin compiler is capable of creating platform basis compatible codes via LLVM.