> it can purge any content globally in about 150ms

Hmm, how can that be? Light in a straight-line fiber optic cable would take 200ms to traverse a greater circle around the world. Add some bends, relays, routers, not to mention servers, and it'll only get longer...

Are you sure the content is really being purged globally in that time, and not just from your local point of presence?

(Disclosure: I'm an engineer on Cloudflare Workers. I have no idea how Fastly does purges. Just trying to understand what you mean here...)