There are a plenty of plugins that can be used for adding almost any functionality to your WordPress powered site. However, if you’re someone who like to build things from the ground up, then probably you won’t like to make use of the existing plugins. You can roll out your own stuff! When building something from scratch you’ll understand the underlying implementation of the thing that you’re creating, and will even gain skills that might end up using the same skills while working on another WP project.