VariationCache deep dive

Summary

Since Drupal 10.2, we now have VariationCache in core. Previously it lived in contrib and mainly powered the Group module, but now it's also the driving force behind RenderCache, DynamicPageCacheSubscriber and more.

So what exactly is VariationCache, how does it work internally and how do you use it? This session aims to answer all of those questions and hopefully encourages you to use it in your own code.