Why shielding matters more than people think

It's easy to assume a CDN's edge network is doing most of the work, and mostly it is. But every cache miss still has to go somewhere, and if your origin is getting hit from dozens of edge locations at once, a traffic spike can look like an outage even when the CDN itself is healthy.

Designating a single shield location changes that shape entirely. Instead of every edge POP fetching independently, they all collapse through one point close to the origin. The origin sees one request instead of many, and the rest of the network fans back out from there.

It costs nothing to set up and it's easy to forget about once it's on — which is usually a sign it's working.