GWT is a framework developed by Google to implement AJAX technology. This framework proposes to develop the GUI entirely from Java. This code is then compiled into Javascript, to be embedded in a web application. GWT is composed of a client part, Javascript, which is the GUI application, it communicates with a server developed in Java. Past the discovery of this excellent framework, a question light in my mind: What are the correct patterns and designs code to implement this framework? Let’s take an example, look at the problems and propose improvements to emerge a coherent design. We have a Toy Project, which consists of a login screen. This example, deliberately simplistic, offers the following GUI: