In this chapter, we started out with the most common, simple Flask application architecture and explored a few of the ways in which we can extend it in order to allow for a more modular approach. We first went from a module-based layout to a package-based one and then graduated to the use of Flask blueprints, which paved the way for the basic application structure that we will use in the following chapters.

In the next chapter, we will use the knowledge that we gained here to create our first functional Flask application by utilizing the blueprint pattern and several well-known Flask extensions.