8. Caching: Azure Managed Redis / Azure Cache for Redis

In-memory cache for sessions, hot data, rate limiting, distributed locks, pub/sub. Use with IDistributedCache (AddStackExchangeRedisCache) or HybridCache's L2. Patterns: cache-aside, write-through, expiration, cache stampede protection. Microsoft is moving customers from Azure Cache for Redis to Azure Managed Redis (newer offering based on Redis Enterprise).