The document discusses Kotlin multiplatform development. It introduces Kotlin multiplatform and its mechanism of sharing common code across platforms like JVM and JS. It covers limitations like missing common libraries and language features limited by platforms. Good parts include same Kotlin API and behavior across platforms. Example use cases presented are business logic in common module, isomorphic web apps, and client apps with common code sharing across platforms. It concludes that while more complex than single-platform development, Kotlin multiplatform is worth the effort and its potential will grow with more shared libraries.