Learn how to identify and fix over 300 of the most common mistakes made in Ruby on Rails applications. Avoid those code pitfalls that reduce code quality, performance, stability, scalability, and maintainability.

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(available in paperback and Kindle)

Far from being an academic textbook, each AntiPattern was pulled from real world applications that we have encountered and successfully refactored throughout our careers.


I have a love affair with this book. Every section of every chapter has given me practical refactoring advice, and for every section I find myself putting the book down in order to dig into my current project and apply what I'm learning about.
I would recommend this book in a heart beat (and I already have... many, many times). Great job guys! I really appreciate the effort you put into writing this book! You have restored my faith in Rails authors!
The authors obviously have deep knowledge of and passion for Rails, and this translates well on the page.
This book rules. There are so many good suggestions and I would say almost every Rails developer has encountered these messy situations before and scratched their head wondering what the best approach is to tackling it.
Everything I read in the book I can apply to the projects I work on everyday. Whether you're new to Rails or an old hat, this book will help you write better Rails applications. Read it, think about it, and apply it.
It's nice to have guides like Chad and Tammer there to suggest improvements to my technique. Highly recommended for anyone novice or intermediate Rails developer.
I’ve been writing Rails code for a long time, and this book is embarrassing to read. ... Truly, this book has the goods on any number of things you’re doing wrong with your Rails app, and I would advise you to take seriously their advice.
Rails AntiPatterns by Chad Pytel and Tammer Saleh is the single greatest rails book a beginner can read. Hats off to you guys. THANKS! Awesome!

Tammer Saleh
Director of Engineering at Engine Yard

Tammer is an experienced Ruby on Rails trainer and speaker with a history rooted in Systems Administration. While working at thoughtbot, Tammer wrote the Shoulda testing framework, and the Hoptoad service.

Follow Tammer on twitter, or read more about him at tammersaleh.com.

Chad Pytel
Founder and CEO of thoughtbot:

Chad's Ruby on Rails consultancy, thoughtbot, embraces both agile development methodologies and a “getting real” project philosophy. Chad has also coauthored Pro Active Record: Databases with Ruby and Rails and has presented at various conferences around the world.

To read more of Chad and the rest of the thoughtbot team’s ideas on development, design, technology, and business, visit their blog!