Having worked at AWS: us-east-1 is probably the easiest region to deploy in (it's old, it's popular, every AWS service is available there), but might just be the worst region to rely on (it's old, it's popular, and every AWS service is available there—but only most of the time).
I vividly remember when AWS Fault Injection Simulator first launched, posting a meme in the #aws-memes slack channel posting a drake meme with the first panel being "Using AWS Fault Injection Simulator", and the second "Deploying in us-east-1".
I will never understand why anyone in our infrastructure team thought for a moment that putting our backup datacenter in us-east-1. And why nobody else tried to get him fired.
That's like buying a backup generator from a guy that wants to meet you in the Walmart parking lot.
