CDN Implementation

Cloudflare for all-in-one (CDN + WAF + DDoS + DNS). CloudFront for AWS-native with Lambda@Edge. Fastly for real-time cache purging and VCL programmability. We select based on your existing infrastructure, traffic patterns, and feature requirements. Multi-CDN setups get considered for critical workloads where single-provider risk is unacceptable.

We define caching rules per content type: static assets (long TTL, immutable where possible), API responses (short TTL or stale-while-revalidate), and dynamic content (bypass or edge-side includes). Cache keys get configured to avoid over-segmentation — stripping unnecessary query parameters and headers. Tiered caching reduces origin fetches from global PoPs. Cache hit ratio targets: 85%+ for content-heavy sites.

Origin shield collapses cache misses from hundreds of edge PoPs into a single request to your origin. This protects your origin from thundering herd problems during cache expiration. We configure shield region placement near your origin for minimal latency. Connection pooling and keepalive settings prevent overwhelming origin servers with new connections on cache miss.

Cache purge integrates with your deployment pipeline — deploy triggers targeted purge of changed assets, not a full cache flush. Surrogate keys (tags) enable precise purge targeting. Monitoring tracks cache hit ratio, origin request volume, edge latency by region, and error rates. Alerts fire when cache hit ratio drops below threshold or origin error rates spike. You see the CDN's impact in real numbers.