[lykr0n]

You give CloudFormation a list of instructions. It accepts it and gives you an ID to watch for updates, then it goes off and executes them.

Terraform executes a list of instructions. It executes them in front of you while you wait.

Both are fine until you run into something like this:

I'm pushing a Elastic Container Service Task Definition change via CDK. A CloudFormation change is submitted, and I wait for it to finish. In the background, it's trying to do the update but the update fails due to some misconfiguration with the new container.

CloudFormation doesn't fail or return an error. It times out after an hour and reverts the change. I have to know to dig into the AWS console to find my failed tasks to view the error.

If I did this update via Terraform, I would get the error back in my console quickly as Terraform is directly telling ECS to make the change. With CDK, the CloudFormation changeset is generated, it is submitted to CloudFormation, then the tool polls the AWS API for progress updates. Sometimes you get specific messages back, sometimes it fails and you need to go in and see what it failed on.