So you have say 3 Region deployment are you saying that you are running 50% more instances than you need in 2 regions that are not US East to make sure you will have capacity when US East goes down :) ? I somehow seriously doubt that.

so you’re suggesting entire regions go down at once or one of the AZs? An entire region doesn’t go down. So again, you are not building for high availability.

US East as a whole went down several times plus a number of incidents when S3 or other critical services went down for the whole region.

i don’t remember seeing us-east go down in its entirely. show me supporting evidence or this is FUD. multiple DCs physically separated, different flood planes make up a region. it’s not easy to down an entire region. the biggest event they had, the S3 one you’re talking about, effected only 2 AZs and didn’t allow new EC2 instances to start and iirc some EC2 instances failed as well. this is a far cry from the entirely of us-east having an outage.