[rcrowley]

Author here: I have settled on account per service per environment with a couple of exceptions.

Sometimes I run multiple services in one account if they’re so tightly coupled as to be useless as a group if any one is down. (This has practically come up when two services are codesigned to multiplex TCP connections to support tens of millions of clients.)

Sometimes I run a single stateless production service in two accounts and route 10% of traffic to the canary account and 90% to the other one.