hook_permission has been removed from Drupal 8, but there is a way to define permissions programmatically.
When developing modules for Drupal, there inevitably comes a time when you may need to include an external CSS or Javascript plugin or library for your project.
Adding Composer packages to Drupal 8 is pretty easy.
If you use Gulp or Grunt in your projects, there is a chance you can may inadvertently trigger a segmentation fault on the server. This is a very unusual error to see in Drupal, and it can be hard to track back what actually caused it.