Interesting combination of basic and slightly intermediate R or R intro. Chapter 4 seemed to derail the book substantially. The chapter on debugging was oddly missing the use of `debugger` and the opportunities to use Pry for debugging outside of Tests which was odd since it was so prominent in the testing chapter.
I got a lot idea to make my Rails app be better. But this book has less detail about Rails. I think this is for experience Rails developer, not beginner. I recommend it for Rails developer who want to improve your skill.