[Thaxll]

This architecture is flawed, your DNS does not seems very resiliant. Also good luck with DB replication across region and the nasty side effects you can get with out of sync data.

My advice is: have a well designed architecture in a single region with multiple AZ and you will cover most problems.

[forelse]

Flawed how? Route53 claims 100% uptime. Though if goes down, options are limited anyway. Are you saying a read replica won't stay in sync? Lag time on replication tends to be low. Keeping databases in sync across regions is definitely difficult, so i recommended against that.

Being in multiple AZs alone seems to be insufficient more and more. So the point was that by at least pushing backups or replicas into another region, you have options to restore from them.

[shiftpgdn]

You could host your DNS elsewhere. Cloudflare (though they recently had a serious outage) or any of the million DNS providers that have been around forever.