Redis

An open-source database that keeps all its data in memory, which makes it extremely fast. Most often used as a cache.

What it tells you about a developer

Redis on a profile usually means backend work at meaningful traffic, because small projects rarely need it. It travels with the practical scaling skills: caching strategy, session handling, background jobs. A developer who can explain what they cached in Redis and why is describing real production performance work.

Type
Database
Released
2009
Used in
BackendInfrastructure & DevOps

Redis holds its data in memory instead of on disk, so reads and writes finish in under a millisecond. Teams put it in front of a slower database as a cache, and also use it for job queues, session storage, and leaderboards. It appears in most production backends operating at real scale.

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