Before he started with Ext JS, he was a Java and PHP developer. He is a JavaScript Evangelist, and started training teams on JavaScript and Ext JS. Readers will learn how the Ext JS components and widgets work, and will be able to use the powerful layout system that Ext JS 4 offers to focus on the new MVC pattern and good architecture. Using the best of templates, dataviews, and grids, users can change the default theme of the library easily with compass and sass, and create custom themes.