The weak link is DNS and routing (e.g. a BGP issue from a third party you don’t control) in this scenario. Using two or three CDNs, you should be good handle ho

The weak link is DNS and routing (e.g. a BGP issue from a third party you don’t control) in this scenario. Using two or three CDNs, you should be good handle hosting easily for static assets. A BGP issue might bring down the website for a country or a city or a continent for 5 hours. That is not something you can control. Same goes with DNS, there is caching, probably a load balancer might get updated at some point and a PHP app that has cached the DNS might miss a hit or two before invalidating. It’s an interesting exercise.