The book Patterns of Enterprise Application Architecture (PoEAA) laid the blueprints for Rails’ architecture. However, as applications growing more and more complex, developers are starting to realize these default architectural patterns come with Rails may not scale very well. In the post PoEAA on Rails, I walk you through some enterprise patterns from the same book that Rails’ architecture heavily base upon, and provide suggestions on scaling your Rails codebase.

http://owenou.com/2011/09/24/poeaa-on-rails.html