A while ago I wrote about an idea I’d had to make use of the Varnish forward caching proxy as a CDN. As it happens I’m not the only one who’s had the idea. There are companies offering Varnish as a CDN in SaaS (or IaaS) form out there but the prices I seen for the minimum offerings were definitely above the average WordPress site’s CDN requirements and budget.
If other companies are using a similar system and charging for it then it seems like the idea is a good one. As it happens it’s not all that hard to implement. In fact this very site is using Varnish as a CDN right now (inspect the page and look at one of the static resources in the network tab and you should see some Varnish Headers).
A bit of testing testing and configuration and 2 hours later it was ready to be put in production. A single DNS change to point it towards the Varnish Server and it was live.