When Marcin Padjdzik suggested that we fly to Poland to give a talk at a DrupalCamp, I jumped at the chance. He later mentioned how surprised he was not to have to convince me!

Currently Drupal core does not offer any hook to do actions after a node/entity is inserted/updated/deleted in Database.

If you want a calendar on your Drupal site, the FullCalendar module is one of your very best options. Some of the advantages of the FullCalendar module include:

tl;dr: I passed, the exam is better than I was expecting, but I still have mixed feelings about Acquia's Drupal Developer Certification program.