This book is intended for the intermediate Scala programmer who is interested in functional programming and works mainly on the web service backend side. Ideally she has experience with libraries like Akka HTTP and Slick which are in heavy use in that area. However maybe you have wondered if we can't do better even though aforementioned projects are battle tested and proven. The answer to this can be found in this book which is intended to be read from cover to cover in the given order. Within the book the following libraries will be used: Cats, Cats Effect, http4s, Doobie, Refined, fs2, tapir, Monocle and probably others. ;-) This edition includes a chapter about migrating the project to Scala 3. Which includes all the nasty issues that we tend to run into if we touch code after a longer time. Code and book source can be found in the author's github account.

Jens Grassel is the CTO and founder of Wegtam, a company specialised in data integration and search technology. He is programming in a plethora of languages and engineering software systems since the fall of the Wall. For some years now his focus has shifted to functional programming languages. He has contributed to numerous free software projects and likes to apply free and open source technologies wherever applicable.