As an example of the use of the SOLID design principles, let's build an application that uses a complex UI design, and see how these principles can help us break up our code into smaller, manageable modules, separated by interfaces.
In this section, we will build an Angular application that will provide a left-to-right panel style page layout. We will use Bootstrap to provide a little styling, and some CSS-based transitions to slide panels in from the left or right. This will provide the user with a slightly different browsing experience to the common up-down scrolling design that most websites utilize.