Backend concept

HTTP & CDN Caching

Cache-Control, validators, conditional requests, shared caches, CDN layers, and invalidation propagation.

Practice this concept Review missed items Back to concept map

Key takeaway

Cache-Control, validators, conditional requests, shared caches, CDN layers, and invalidation propagation. Start with the related games below when you want to turn the definition into practice.

Why this matters

HTTP caches improve latency and cost only when freshness, privacy, and revalidation rules are correct at every layer.

How to practice

Separate browser, shared-cache, and application-cache responsibilities before setting policy.

0 active misses 0 reviewed 0 games completed

Local review for this concept

No local review items for this concept yet.

Start a focused review session for HTTP & CDN Caching.

Learning objectives

Select explicit browser and shared-cache policies.
Prevent personalized response leakage.
Use validators and Vary correctly.
Use validators for selected representations.
Operate targeted CDN invalidation.
Bound emergency stale response behavior.

Common mistakes to avoid

Caching personalized responses publicly.
Treating no-cache as no storage.
Omitting Vary for negotiated representations.
Sharing one strong ETag across different bytes.
Restarting origin to purge a CDN.
Serving stale sensitive data.

Games for HTTP & CDN Caching

Start with the first game, then use local review history to revisit missed decisions.

HTTP Caching Intermediate

HTTP Cache Policy Lab

Choose browser and shared-cache policies for public, personalized, validated, and variant API responses.

Time: 7-10 minutes
Concept: HTTP cache policy and sensitive response boundaries

Play HTTP Cache Policy Lab

HTTP Caching Advanced

ETag & CDN Revalidation Lab

Follow validators through browser, CDN, and origin while handling 304 responses, representation variants, purge, and bounded staleness.

Time: 8-12 minutes
Concept: Conditional requests and CDN cache operation

Play ETag & CDN Revalidation Lab

Caching Beginner

Cache Eviction Lab

Predict cache hits and misses as requests flow through an LRU cache, then experiment with TTL behavior and stale data tradeoffs.

Time: 5-8 minutes
Concept: Cache hits, misses, LRU, TTL, and stale data

Play Cache Eviction Lab