I'm doing a port of a Kotlin/JVM to multi platform (JVM/Js/Native), is there any libraries I can call on for basic file i/o aka read a text file to a string and write a text file to a string (i assume it exist but I can't find it). Also I've got concurrency in the JVM version using worker threads (read jobs from a task queue and write results to a result queue), any multi-platform equivalent library?

Concurrency: There's a Worker in native. You could probably build a simple wrapper around that. I don't know if there's a supported library around that kind of simple threading, though.

Thanks