Performance
CDN
Content Delivery Network
A Content Delivery Network (CDN) is a globally distributed set of caching servers that serve static assets and (increasingly) dynamic content from a location physically close to each user, dramatically reducing latency.
In depth
CDNs work by pulling content from your origin once and then serving subsequent requests from edge nodes around the world. A user in Tokyo requesting a CSS file hosted in London gets it from a Tokyo edge node instead of crossing the Pacific.
Modern CDNs (Cloudflare, Fastly, AWS CloudFront, Vercel Edge) also run code at the edge — image resizing, A/B test routing, full HTML rendering — collapsing TTFB to under 100 ms globally.
Why it matters
Putting any public site behind a CDN is one of the cheapest, biggest performance wins available. It also provides DDoS protection, TLS termination, bot mitigation, and access logs — essentially free upgrades that come with the caching.
How Lemwatch helps with cdn
Lemwatch monitors cdn continuously and alerts you the moment something changes.
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Browse the full Lemwatch monitoring glossary (47 terms).