It's heavily CPU intensive code that needs to perform async operations on rare occasions. Since async adds overhead in every function call, code that calls a lo

It's heavily CPU intensive code that needs to perform async operations on rare occasions. Since async adds overhead in every function call, code that calls a lot of functions will be slower. The problem with the Kotlin implementation is that if you ever want to be able to call a single async function, every call higher in the stack must also be async (unless you have a separate runner, but that's not always possible, and even if it is you can have surprising results)