The correctly implemented ViewModel hierarchy in Ext 5.x MVVM applications provides for more robust, modularized and well-written large applications. Read this article to write big, yet maintainable, expandable and bugless applications.
Although Sencha Cmd is a very useful tool for application scaffolding, creating view, controllers and models, sometimes it is faster to use a single-file app. It is especially useful for fast testing, prototyping or concept proof. Read how to do it.