Redis Has a Free In-Memory Data Store — Cache, Queues, and Pub/Sub in One Tool

Redis stores data in memory for sub-millisecond reads. Use it as a cache, message queue, session store, rate limiter, and real-time leaderboard — all in one tool. More Than a Cache Most developers use Redis for caching. But Redis is a full data structure server with use cases far beyond cache. What You Get for Free Data structures: Strings — cache values, counters, flags Hashes — user profiles, object properties Lists — queues, activity feeds, recent items Sets — tags, unique visitors, intersections Sorted Sets — leaderboards, priority queues, time-series Streams — event sourcing, message queues (like Kafka-lite) Pub/Sub — real-time messaging between services Common patterns: # Cache with TTL SET user:123 '{"name":"Alice"}' EX 3600 # Rate limiting INCR api:rate:user:123 EXPIRE api:rate:user:123 60 # Leaderboard ZADD leaderboard 1500 "player1" ZADD leaderboard 2000 "player2" ZRANGE leaderboard 0 9 REV WITHSCORES # Job queue LPUSH jobs '{"type":"email","to":"alice@test.com"}' BRPOP jobs