leanpub, Gradual Modularization for Ruby and Rails: Improve collaboration, system design, and flexibility https://leanpub.com/package-based-rails-applications by Stephan Hagemann is the featured book on the Leanpub homepage! https://leanpub.com #RubyOnRails #SoftwareEngineering #SoftwareArchitecture #ComputerProgramming #Ruby