No matter the frameworks you use and the code you write, the most important is the model that you define to create your application. System Designer helps you to design this model and to generate the classes and components to build your application.
System Designer uses UML, a standard, to define your model. So you probably already know how to create a model in System Designer even if you have never run it.
Once you have created your model, System Designer generates the skeletons of all your methods. You only have then to add your code to implement them.
System Designer provides you helpers to manage your components. You can easily navigate threw components to create your application.
There is no need to code to instantiate a component. Create a component in System Designer is like creating a document in a NoSQL Database.
In fact, System Designer acts as an ODM (Object-Document Mapper) to manage your components as NoSQL Documents.
You can run your application directly from System Designer and then export it to HTML, JSON or a Node.js module (* macOS and HTML5 version only).
Because you have defined a model for your application, a Dynamic Type Check is done on every action of your application. All warnings are send and shown in System Designer.
System Designer can load the model of any application that runs on the browser or on Node.js (* macOS and HTML5 version only). You can see the schemas, models, components and methods of the running application and you can edit them.
All modifications to the model done inside System Designer will be send to the running application. There is no need to reload to see your modifications.
System Designer has a Github module to synchronize your work between all these apps. You can begin your design on your Mac and then continue it on your iPad.
System Designer is part of the Design First project. Design First is a set of tools to help developers to design before coding.