# Why Redis Is Fast
AI-readable version of this post.
Path: /systems/why-redis-is-fast
Category: Systems
Date: 2015-06-01
Author: Infrastructure
Reading time: 1 min
Description: In-memory data, focused primitives, and event-loop simplicity.
## Memory first

Redis keeps the active data set in RAM, removing disk latency from the hot path.

## Event loop

A mostly single-threaded execution model avoids lock contention for core operations.

```tsx
while (true) {
  const events = waitForSockets();
  for (const event of events) executeCommand(event);
}
```

## Tradeoffs

Heavy commands can block progress, memory is finite, and persistence/replication choices affect behavior under failure.