Application architecture is as much about providing structure and consistency as it is about actual classes and framework code, and building a good architecture unlocks a number of important benefits. In Ext JS 5, we're adding optional support for the MVVM architectural pattern. Although MVC and MVVM are very similar software patterns, using MVVM has some specific benefits that can vastly reduce the amount of application logic developers need to write. Learn how and when to use the MVC and MVVM patterns.