What's the best way to run a cross-region deployment on Heroku?
Yes, this is completely possible, you would need to choose the AWS region for each record that matches the Heroku region in question. e.g
foobar.example.org CNAME myuseast.herokuapp.com -> latency based us-east-1foobar.example.org CNAME myeuwest.herokuapp.com -> latency based eu-west-1This link explains how to find the regions, eu = eu-west-1, us = us-east-1Where are Heroku apps hosted exactly?
It is important to consider that users who have similar pings to both US and EU data centres may get routed to one one day and the other the next.
This link explains that this is possible, I have also tried it in my own AWS account just now. https://docs.aws.amazon.com/Route53/latest/DeveloperGuide/resource-record-sets-values-latency.html