Nowadays, writing side effects free programs is very critical. As requirements are becoming complex day by day, Functional Programming can help us in this situation. This book will not only help you learn basics of Functional Programming with Kotlin, but will also show you how to apply them to real-life projects with popular libraries like ...
It's a very short briefing of Kotlin functional features, showing simple and little examples of code using Kotlin, Spring or Arrow. I use Kotlin and Spring for one year now and I've also seen some Kotlin code integrated with Arrow. Definetely it's not a "Kotlin in Action" or "Effective Kotlin" kind of book.