[DEE-450] Caching and Search Overview

This DEE is a category overview for Caching and Search principles.

DEE-451 Cache-Aside Pattern -- the most common caching strategy where the application manages cache reads and writes explicitly
DEE-452 Read-Through and Write-Through Caching -- patterns where the cache layer manages database interaction transparently
DEE-453 Cache Invalidation Strategies -- TTL-based, event-driven, and versioned approaches to keeping caches fresh
DEE-454 Redis Data Structures for Caching -- choosing the right Redis data structure for your access pattern
DEE-455 Redis Persistence (RDB vs AOF) -- choosing between RDB snapshots, AOF append log, and hybrid mode for data durability
DEE-456 Distributed Locking with Redis -- single-instance locks, Redlock, and the safety debate around distributed coordination
DEE-457 Redis Pub/Sub and Streams -- fire-and-forget Pub/Sub vs persistent Streams with consumer groups
DEE-458 Full-Text Search with Elasticsearch -- relevance-scored search with inverted indexes and data synchronization patterns

[DEE-450] Caching and Search Overview ​