Redis cache in system design: where it helps and where it hurts

Redis is powerful when it is used for the right reason. It can reduce database load, improve latency, and support high-throughput read paths.

Good use cases

Use Redis for frequently accessed data, computed results, sessions, rate limiting, counters, and temporary state.

Common mistake

The most common mistake is caching data without a clear invalidation strategy. Every cache needs an answer for when data changes.

Production checklist

Define TTL, fallback behavior, cache key format, serialization format, monitoring, and memory limits before using Redis in critical paths.