I'd just like to point out that there are considerations other than latency that you should be thinking about. Sure, you can optimize for latency, but just wait and see what happens when you get hit with a DDOS attack...
They could remove the affected servers from Route 53 and point to some other region until the DDOS stopped. True, they'd have to use a small TTL and clients using a bad-behaving DNS might receive the wrong IP for a while, but depending on their SLA, that might be acceptable.
Would something like Anycast allow them to failover faster? I would imagine route propagation isn't instantaneous either, so I'm curious how big the difference would be.
Would something like Anycast allow them to failover faster? I would imagine route propagation isn't instantaneous either, so I'm curious how big the difference would be.