This is not a great book about Scala。 It is 500-something pages after which you will have to read another book。 It also has almost all of the major flaws of programming books。 Feels like someone was playing Bingo。Key negative points: - The book goes in-depth and repeats itself on easier topics。 On topics that are almost copy paste of Scala docs。 There are probably 150 pages total spent on map， flatten and flatMap concepts for each type。 Yet， when it comes to complex fundamental topics the book j This is not a great book about Scala。 It is 500-something pages after which you will have to read another book。 It also has almost all of the major flaws of programming books。 Feels like someone was playing Bingo。Key negative points: - The book goes in-depth and repeats itself on easier topics。 On topics that are almost copy paste of Scala docs。 There are probably 150 pages total spent on map， flatten and flatMap concepts for each type。 Yet， when it comes to complex fundamental topics the book just literally flies through them， at best uses them without explanation， at worst just implies that reader knows a lot about FP or OOP。 - The book spends roughly 1/3 of its volumes on libraries。 When， again， not explaining some core concepts in depth。 Libraries that rely on complex Scala topics （that are not explained in the book） are thrown in as is in the very beginning of the book。 - The book spends pages on syntax/examples/descriptions of random tasks that are hard to follow。 It can define a class and then use it after 20 or so pages。 It can spend a whole page on just a copy paste of a code example， of which you are really only interested in 2-3 lines of code。 - The book can have a chapter on a core concept of the language that is not present in other languages。 Which is good。 And then 3-4 chapters later use some feature of it that was not explained in the original chapter。 Literally pointing an arrow at it with 1-2 sentence paragraph about what it is。 - The capstone projects are。。。 weird。 3rd or so capstone project makes you write a REST API using a library that heavily relies on Streams， Encoders and Decoders。 And the NEXT chapter after that teaches you what List is （and yes， List is also used in capstone project before it is even introduced）Overall this is either editorial mistake or the author could not focus on the kind of audience they expected。 A book for beginners？ Then don't fly over complex fundamental topics。 And explain why map methods are so important。 No need to copy paste docs for each type even for beginners。 A book for experienced engineers？ Then go in-depth on complex Scala specific features and don't repeat the syntax of map and flatMap。The only thing this book can teach is how to solve specific artificial problems given in the book itself。 And this is hardly 'teaching' Scala。 I rarely give such negative reviews but whether you are a beginner or an experienced engineer I would say avoid this book and don't waste your time。 。。。more