We've found a few interesting caching problems in Drupal 8 that have interesting implications when you are working at scale where Varnish and other CDNs will display "stale" content. We'll look at a few real-world case studies using views, multilingual, and other default Drupal core features.  Recommended background: Basic understanding of Drupal 8 - and be able to follow through a walk through of settings and symptoms.  Quick summary: Attendees will be alerted to some of the gotchas and caching problems that can be found in minimally modified Drupal,  and some ways to avoid them.