With Drupal 8 a lot is configured instead of programmed. So the key is to find out how it comes together. Graph API helps rendering these configurations.
Having a Drupal 8 site under development with a customer aware of the risk of loosing data I took the risk of fixing a broken Drupal 8 site. Today I did an code update and got the following welcome screen on http://drupal.dev
If you have just changed code (for example deployed a new module or moved an existing one) read http://drupal.org/documentation/rebuild
Additional uncaught exception thrown while handling exception.
Original
Playing around with Drupal 8 together with Graph API and Graph I generated this UML through admin/config/system/graphapi/uml/Drupal\views\Plugin\Core\Entity\View ... it has some rough edges still.
Tell us what you think of this UML Diagram and your needs to have on site information.