Something funny (well, kind of sad) about CloudFormation I noticed this summer was that if you deploy a CloudFormation stack which updates a ECS service and deploys tasks which then fail health checks, CloudFormation will do nothing about this and just let ECS keep killing and restarting tasks for.. well, at least several hours. You have to know to go into ECS and drain the tasks manually and then initiate a rollback from CF to get your service back into a good state. The bug reports about this I found were going back years.
The upside is that I got really well acquainted with how ECS worked.
The upside is that I got really well acquainted with how ECS worked.