There once was a time that building your own CDN would have been unthinkable - complicated, expensive and not worth the hassle, considering that there were a number of well-known commercial CDN providers available who could make it easy to distribute content reliably across the geographies a company wanted to reach. CDN vendors offer the full package: hardware, software, network and so on, meaning that, for a long time, for most companies, convenience trumped other considerations.
Not so long ago and not so far away, the idea of building your own CDN was a complex, remote and expensive proposition, requiring more technical expertise than most companies delivering digital content wanted to commit when there were perfectly reasonable commercial CDN options available.
When using a traditional CDN or caching system, creating user-centric security and access policies can be a complex and performance challenging undertaking. Not only do you have to pull user data from a backend, but you then have to apply the security policies from that data onto the request. VCL is an excellent candidate for the latter problem of applying security policies to requests. This leaves the problem of how you get user data (JSON) into VCL? How do you do that on a user-by-user basis? And how do you do that in a way where you keep backend communication to an absolute minimum, or put another way, serve as much data from cache as possible?
Content delivery is a much-hyped and important topic - one that we’ve engaged with and developed technologies around for years.