Redis
Redis is where we put the work that has to be instant — caches, sessions, rate limits, and queues — so the database does less and the product feels faster.
Redis is an in-memory data store that serves reads and writes in microseconds. Beyond caching, it provides primitives for queues, pub/sub, counters, and leaderboards.
Most slowness is repeated work. A well-placed cache, a rate limiter, or a background queue on Redis takes pressure off the system of record and turns a sluggish endpoint into an instant one.
In the product,
not the slide.
Caching
Hot data served from memory so expensive queries run once, not on every request.
Queues & jobs
Background processing for emails, webhooks, and anything that shouldn’t block the user.
Rate limiting & sessions
Fast counters and session stores that protect the API and keep auth snappy.