On the SitePoint PHP blog today there's a new tutorial (by Daniel Sipos) talking about the Drupal 8 cache and showing how to use it in an example, caching the latest post data pulled from the Drupal content.
Drupal 8 comes with many improvements over its predecessor we have grown to both love and hate. Next to prominent systems such as Views in core, configuration management or a useful translation service, there are also less known changes but that are equally important to know and use. One such improvement has been the cache API that solves many performance problems we have in Drupal 7.
They start with a basic introduction to the new cache handing and how the caches are separated out into different "bins" rather than all stored in one place. He includes sample code showing how to: save data to the cache, getting information back out and invalidating the cache to be handled by garbage collection. He also covers the cache tags, a feature that allows you to "tag" items across multiple caches and remove/invalidate them all at the same time. He wraps up the post getting into the more practical example showing the caching at work in a controller caching the contents of the posts to the Drupal site.