A must read for anyone willing to learn and understand how to write concise and maintainable tests, and how to grow a code base in an object oriented fashion. The techniques and principles shown in this book are pure gold: walking skeleton, depth of testing, async code testing, data test builders, mocking, single responsibility, only mock classes you own, hexagonal architecture, etc. If you're still in the fence about the advantages of TDD, this is for you. It displays how quick it is to add new features and make changes with the confidence that you aren't breaking other parts of the system.

However, the only reason I won't rate it a 5 star is that this book study case, which is great if you persevere through its setup and try it out yourself, takes time to understand the techniques they are using. If you try the code it won't compile sometimes, there will be missing code and setting up the server is tricky (you can checkout my GitHub project which have a README to help you out on this github.com/vrcca/auction-sniper). Nevertheless, I must say that writing it myself helped a lot! It's way easier to understand the project navigating the code through an IDE than a book.

To sum up, this is an amazing book for the beginner and the experienced. It may take some time and TDD experience to swallow it, but it's totally worth it.