Caching

Storing computed/fetched results to avoid repeat work — see also Networking/CDN for the delivery-layer angle.

Why we need this / what value this brings

Avoids repeating expensive computation or DB round-trips for data that doesn't change every request.

When to use this

Once a specific read path is measurably slow or the DB is under load from repeated identical queries — not preemptively.

How to use or implement this

Cache the narrowest thing that's actually expensive (a computed value, not a whole page) and set a TTL you're comfortable serving stale.

Subtopics

• ApplicationLevel
• CDN EdgeCache
• CacheInvalidation Strategies
• EvictionPolicies LRU LFU FIFO
• InMemory Redis Memcached
• PopulationStrategies ReadThrough WriteThrough WriteBehind WriteAround

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Empty folder — drop notes, links, and findings here as you research.