Let's try to visualize how our application should work.

Our users will definitely need to register, so we'll be able to grant them the ownership of their own tests; once done, they will be able to create a new test. Each test will have a name, a description, a list of questions, and a series of possible results; each question will have a descriptive text, a list of answers, and an optional image; each answer will have a descriptive text, an optional image, and a list of score points; and each result will have a descriptive text and a score value.

The score points and the score value will be extensively discussed later on. For now, we'll just state the obvious--whenever a user completes the test, the sum of score points among all the given answers will be matched with the score value given to each possible result in order to determine the final outcome. The numbers will be shown or hidden to the user as per the test owner's choice.

That's about it. It might sound easy or not, depending on our programming experience, but one thing is certain--we got a plan.

Now that we have identified the key features, let's break them down into a list of development topics:

• Routing: The application will have to properly respond to client requests, that is, routing them according to what they're up to.
• Data model: We'll definitely adopt a database engine to store our tests, questions, answers, and so on; hence, we'll also need to develop the proper tools to access it in a modern, fashionable way. In order do so, we need to define our data architecture by setting up data repositories and domain entities that will be handled by the server and hooked to Angular through the most suited ASP.NET Core interface to handle HTTP communications--the Controller class.
• Controllers: From an MVC-based architectural perspective, one of the main differences between multi-page and single-page applications is that the former's Controllers are designed to return views, while the latter ones, also known as API Controllers, mostly return serialized data. These are what we will need to implement to put Angular components in charge of the presentation layer.
• Angular components: Switching to the client side, we will need to define a set of components to handle UI elements and state changes. As we probably already know, components are the most fundamental elements in Angular, replacing the AngularJS controllers and scopes. We'll get to know more about them soon enough.
• Authentication: Soon enough, we'll have to deal with user login and registration. We'll take care of that by adding a membership context, so we'll be able to limit CRUD operations to authenticated users only, keeping track of each user action, requiring registration to access some pages/views, and so on.
• UI styling: We will take our time to come to that, as we will stick to the core topics first, but we'll definitely get there eventually; the initial ugliness of our web client will flourish into a responsive, good-looking, and mobile-friendly user interface.

These will be our main development challenges. As we said earlier, we definitely have to understand how to properly handle each one of them, or we won't be able to succeed. Hence, let's get to work without further ado!

The following chapters will guide us through the journey; we'll also cover other important aspects such as SEO, Security, Performance Issues, Best Coding Practices, and Deployment, as they will be very important later on.