The nature of application development has swung away from large, tightly integrated (some might say "coupled”) behemoths into loose collections of highly-granular functionality. This is true both within an application, through tools like Ruby's metaprogramming facilities and flexible typing, and among a suite of applications, enabled by single-sign-on security architectures and widely available robust messaging providers. This talk will demonstrate these techniques and look at the benefits of this application style, from maintainability, testability, to scalability and sanity. This talk is code-heavy, slide-light, and requires the attendee to have a firm grasp of Ruby, Rails, and patterns of application architecture.