Redis
In-memory data structure store. Cache, queue, rate limiter, session store, pub/sub, and stream broker — all in one binary.
Cache / In-memory Beginner
Category
Cache / In-memory
Difficulty
Beginner
When to use
You need sub-millisecond access to small hot data — caches, counters, queues, rate limits, session state.
When not to use
You need durable primary storage, ACID across keys, or you're paying for RAM you don't need.
Alternatives
Memcached DragonflyDB KeyDB Valkey