Drupal allows configuring explanation and submission guidelines for each content type. How to display those on a custom route ?
Drupal core provides out of the box a "new" indicator to tell users when there is a new content for them, such as nodes or comments. How to implement this in a custom controller ?
How to rename uploaded files with programmatically generated random names on Drupal 8/9.
How to programmatically create a dynamic menu link (and pass it an argument).
In this tutorial we will see how to implement a custom form template in drupal 8. Implementing custom form template is a basic if you want to get fully customizable HTML code and make a lot of sens if you are working with toolkit such as bootstrap.