Drupal Caching

Philosophy: Configuration first. Prioritize declarative caching (cache metadata in render arrays, config schema for cache backends) over programmatic approaches.

I need to...

I need to...	Guide
Understand Drupal's caching layers and when to use each	Cache System Overview
Learn the three pillars of cache metadata	Cache Metadata Trinity
Add cache tags to invalidate on entity/config changes	Cache Tags
Vary cached content by URL, user, language, etc.	Cache Contexts
Set how long content can be cached	Cache Max-Age
Choose and configure a cache backend (Redis, Memcache, APCu)	Cache Backends
Understand cache bins and their purposes	Cache Bins
Cache render arrays and understand render caching	Render Caching
Handle cache metadata bubbling in nested render arrays	BubbleableMetadata & Cache Bubbling
Defer expensive rendering with placeholders	Lazy Builders
Understand anonymous page caching	Page Cache
Cache pages for authenticated users	Dynamic Page Cache
Progressively render expensive content	BigPipe
Invalidate caches when data changes	Cache Invalidation Patterns
Create and invalidate custom cache tags	Custom Cache Tags
Configure Redis or Memcache backends in settings.php	Cache Backend Configuration
Follow caching best practices	Best Practices & Patterns
Avoid common caching mistakes	Anti-Patterns & Common Mistakes
Ensure cache security and performance	Security & Performance
Find core cache files and APIs	Code Reference Map