#🧱 Building Block: Redis

#Overview

Redis (Remote Dictionary Server) is an open-source, in-memory data structure store, used as a database, cache, and message broker.

#Key Concepts

• In-Memory: All data is stored in RAM, providing sub-millisecond latency.
• Data Structures: Supports strings, hashes, lists, sets, sorted sets, bitmaps, etc.
• Persistence: Supports RDB (snapshots) and AOF (append-only file) for durability.
• Pub/Sub: Built-in messaging capabilities.

#Caching Strategies

• Cache-Aside: Application reads from cache, if miss, reads from DB and updates cache.
• Write-Through: Application writes to cache, and cache updates DB.
• Write-Behind: Application writes to cache, and cache updates DB asynchronously.

#When to Use

• Caching: Storing session data, product metadata, or rate limiting counters.
• Leaderboards: Using Sorted Sets.
• Real-time Messaging: Using Pub/Sub or Streams.

#Trade-offs

• Pros: Blazing fast, versatile data structures.
• Cons: Limited by memory size, data durability depends on configuration.