Redis

Redis is the ultra-fast, open-source, in-memory data structure store: a powerful NoSQL key/value database.

This is your go-to for low-latency data operations. Redis operates primarily in memory, delivering sub-millisecond response times for real-time applications (think: session storage, leaderboards, and caching). It functions as more than just a key/value store; it’s a versatile data structure server supporting Strings, Hashes, Lists, Sets, Sorted Sets, and JSON. Leverage its Pub/Sub capabilities for message brokering, or rely on its optional persistence for durability. Deploy it for high-speed caching to offload your primary database, or use it as a primary database for high-throughput microservices.

https://redis.io