AWS has internal dependencies on US-EAST-1.

Admittedly they're getting fewer and fewer, but they exist.

The same is also true in GCP, so as much as I prefer GCP from a technical standpoint: the truth is, if you can't see it, it doesn't mean it goes away.

The only hard dependency I am still aware of is write operations to the R53 control plane. Failover records and DNS queries would not be impacted. So business workflows would run as if nothing happened.

(There may still be some core IAM dependencies in USE1, but I haven’t heard of any.)

We're currently witnessing the fact that what you're claiming is not as true as you imply.

We don't know that (yet) - it's possible that this is simply a demonstration of how many companies have a hard dependency on us-east-1 for whatever reason (which I can certainly believe).

We'll know when (if) some honest RCAs come out that pinpoint the issue.

I created a DNS record in route53 this morning with no issues

the Billing part of the console in eu-west-2 was down though, presumably because that uses us-east-1 dynamodb, but route53 doesn't.

I had a problem with an ACME cert terraform module. It was doing the R53 to add the DNS TXT record for the ACME challenge and then querying the change status from R53.

R53 seems to use Dynamo to keep track of the syncing of the DNS across the name servers, because while the record was there and resolving, the change set was stuck in PENDING.

After DynamoDB came back up, R53's API started working.

We have nothing deployed in us east 1, yet all of our CI was failing due to IAM errors this morning.