Why is reddit relying on only one cloud provider? AWS can/should do better but service providers of the size of reddit should be using mult-vendor set-ups for sure.
They did say in their original post-mortem that spreading the load among multiple availability zones has been on their todo list for a while. It has just taken longer than they expected with their limited engineering staff.
It probably has something to do with the group being very small. Sure they turn a lot of traffic, but there's only so much you can do with a group of their size on what I imagine is still a limited budget.
Sounds like a case of similar to safety systems at a nuclear plant. Not pressing until it is REALLY PRESSING! Its the usual dilemma, investing time/moey on something that most likely wont be needed versus adding that cool feature all the users will immediately see the benefit of. In a competitive environment, it isn't difficult to understand how they ended up on one vendor.
Well, depending on prevailing conditions, they might be more widely dispersed rather than contained within the special "echo chamber" that reddit has built for that purpose.
Is a multi-provider setup common? I certainly think Reddit should be on multiple availability zones within AWS, but spanning multiple providers seems hugely more difficult.