In a previous blog post, I explained the list cache tag for entity types, which you use when displaying a list of entities. This cache tag ensures that appropriate render caches and response caches are invalidated whenever a new entity is created, or an existing one is saved.

One of Drupal's greatest features, and often mysterious underworking to many site builders and developers, are its caching layers especially render caching. We have all been there before: we have no idea why it's not quite working, so we press "Cache rebuild" (or more infamously, "Flush all caches" of the pre-Drupal 8 eras), and like magic, things are displaying properly.

Phil Karlton is quoted as having said, "There are only two hard things in Computer Science: cache invalidation and naming things." As someone who suffers horribly from the latter, I'm glad Drupal's caching APIs make the former a breeze.