Cache-Aside
A caching pattern where the application checks the cache first; on a miss, it fetches from the database and populates the cache. Also called lazy loading.
What is Cache-Aside?
A caching pattern where the application checks the cache first; on a miss, it fetches from the database and populates the cache. Also called lazy loading.
Cache-Aside is a foundational concept that sits in the Caching Strategies area of system design. Engineers reach for it whenever they need to reason about real-world trade-offs in that space — not just for textbook correctness, but because real production systems at companies like Netflix, Amazon, and Google make these decisions every day.
If you want to go deeper than this definition — with diagrams, code, and a quiz to lock it in — work through the "Cache-Aside" lesson linked below. It walks through the why, the mechanism, the trade-offs, and how the giants actually use it in production.
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Full interactive lesson with diagrams, code examples, real-world references, and a quiz.
Open the Cache-Aside lessonRelated lessons
Lessons that touch on Cache-Aside as part of a larger topic.
Cache-Aside Pattern
The most common caching pattern in production, your application owns the cache, not the other way around
foundation · caching strategies
Read-Through Cache
Let the cache handle database reads for you, the application never talks to the database directly
foundation · caching strategies
See also
Related glossary terms you might want to look up next.
Caching
Storing frequently accessed data in a faster storage layer so you don't have to fetch it from the original (slower) source every time.
Write-Through Cache
A caching pattern where every write goes to both the cache and the database simultaneously. Ensures consistency but adds write latency.
Write-Behind Cache
A caching pattern where writes go to the cache first and are asynchronously flushed to the database later. Fast writes but risks data loss on cache failure.