TL;DR Good read for any intermediate Ruby on Rails developer.
I've originally read this book shortly after it came out in 2011. I was reminded of it recently when discussing a solution (I recalled reading in this book about) and decided to write a review.
The concept of presenting ideas via antipatterns should be fairly well known in the programming community. And for good reason. It works and its very effective. By focusing on practical issues the authors saw in codebases and presenting actual solutions that you can apply in your code today they created a good library of solutions to problems that plague Rails codebases to this day. To top it all off most (if not all) of the advice is still relevant even though the book was written in the Rails 3 days.
Some time has passed from the publish date and time wasn't kind to some of the overly specific advice (recommending concrete gems, listing code samples specific to a version of rails etc.). When skimmed, these passages don't distract too much from the good points the book makes. Overall the book is a must-read for any intermediate Ruby on Rails developer. Seasoned developers won't see as much benefit from reading it, but can still pick up a trick here and there.
The book is divided into chapers creating logical blocks of antipatterns and solutions:
This is probably the most interesting part of the book. The chapter deals with the model layer and lists tips and tricks to make code there as expressive and readable as possible. Almost everything mentioned in it is best practice to this day.
The chapter lists some good advice to think about when modelling data. E.g. maybe you don't need to have a full-blown Roles model to store roles on a User model. Maybe you do, but always think about YAGNI.
Provides some good ideas for working with Rails views. Some of the ideas are controversial, but you need to be a seasonsed developer to appreciate the nuances. E.g. The chapter goes on suggesting you use HAML as your templating language. While I agree with the suggestion I know many people don't so keep that in mind when reading it.
The chapter starts by suggesting some older gems as examples of not reinventing the wheel when doing authorization. Other than that all of the tips there are relevant for current apps.
This is a chapter about good programming practices in general. Seasoned developers can skim so that they don't grinn to much when reading they should use a gem to parse out HTML. Others should pay close attention.
This is one of those chapters that you can skip entirely when you know how to select a proper gem when building an app, but is indispensable when you don't.
Some good ideas on testing, but there are much better books written on the topic. The gems listed (e.g. FactoryGirl) is an excelent solution to the fixture problem even today.
Some general tips on not making silly mistakes like forgetting SQL indexes and doing things in the database rather than loading up thousands of objects in memory and doing computations on them.
Very good practices when using database migrations and on validations and the fact that as much of them as possible should be handled by the database.
Again nothing new to seasoned developers, but nicely formulated examples on why you need to be carefull and not have corrupted data as a result of an exception and that your exceptions should fail loudly so that you can do something about the problem.