Chad Pytel & Tammer Saleh 
Rails AntiPatterns [PDF ebook] 
Best Practice Ruby on Rails Refactoring

The Complete Guide to Avoiding and Fixing Common Rails 3 Code and Design Problems As developers worldwide have adopted the powerful Ruby on Rails web framework, many have fallen victim to common mistakes that reduce code quality, performance, reliability, stability, scalability, and maintainability. Rails(TM) Anti Patterns identifies these widespread Rails code and design problems, explains why they’re bad and why they happen-and shows exactly what to do instead. The book is organized into concise, modular chapters-each outlines a single common Anti Pattern and offers detailed, cookbook-style code solutions that were previously difficult or impossible to find. Leading Rails developers Chad Pytel and Tammer Saleh also offer specific guidance for refactoring existing bad code or design to reflect sound object-oriented principles and established Rails best practices. With their help, developers, architects, and testers can dramatically improve new and existing applications, avoid future problems, and establish superior Rails coding standards throughout their organizations. This book will help you understand, avoid, and solve problems with Model layer code, from general object-oriented programming violations to complex SQL and excessive redundancy Domain modeling, including schema and database issues such as normalization and serialization View layer tools and conventions Controller-layer code, including RESTful code Service-related APIs, including timeouts, exceptions, backgrounding, and response codes Third-party code, including plug-ins and gems Testing, from test suites to test-driven development processes Scaling and deployment Database issues, including migrations and validations System design for "graceful degradation" in the real world