Now that's finished, I'm rereading my @pragprog
book from cover to cover for the final editing. I'll share some snippets.

Let's start with: why there are origami on the cover?

https://pragprog.com/titles/uboop/from-objects-to-functions/

From Objects to Functions

Learn Functional Programming by building a complete web application that uses Kotlin, TDD with end-to-end tests, and CQRS and Event Sourcing microservices architecture.