Content Delivery Networks (CDN): Faster Delivery Globally
A Content Delivery Network (CDN) is a globally distributed network of servers (called edge nodes or points of presence) that cache and serve content from locations close to your users. Instead of all users downloading assets from your origin server in a single location, they receive them from the nearest edge node — dramatically reducing latency.
What CDNs Deliver
- Static assets: JavaScript bundles, CSS files, images, fonts, videos — cacheable content that doesn't change per-request. This is the primary CDN use case.
- Dynamic content: Modern CDNs like Cloudflare and AWS CloudFront can cache and serve dynamic content — with intelligent cache rules based on cookies, headers, and query parameters
- API responses: Cacheable API responses (public content, reference data) can be served from the CDN edge
CDN Benefits
- Performance: Reduced latency by serving from geographically close edge nodes — a user in Melbourne gets assets from Sydney, not London
- Reduced origin load: Cache hit rate of 90%+ means your origin servers handle a fraction of the total requests
- Reliability: CDN absorbs traffic spikes and continues serving cached content even during origin failures
- DDoS protection: CDNs absorb volumetric DDoS attacks at the edge before they reach your infrastructure
- Cost: CDN bandwidth is typically cheaper than origin server bandwidth
CDNs We Use
- Cloudflare: Excellent security features (WAF, DDoS), global network, competitive pricing. Our default CDN for most projects.
- AWS CloudFront: Deep AWS integration, excellent for serving content from S3, tight integration with other AWS services
- Fastly: Highly programmable CDN — useful for complex caching logic and edge compute