I'm ex AWS so I used CloudFormation sort of because I had to (I guess, no one told me not to use terraform, but it felt wrong not to drink our own champaign). I left AWS to co-found a startup and when I had to pick between the two, I just used what I knew already (CloudFormation, but more specifically CDK). I have to say I am highly tempted to give Terraform a look, but if I do, it will be terraform + CDK probably: https://github.com/hashicorp/terraform-cdk

For me troubleshooting, speed, and that punch in the gut feeling when you see after 30 mins of crunching the dreadful - update failed rollback in progress - are great reasons to give Terraform a try.

AWS should fix this by making the SDK/API be 1:1 with infra as code. The result of a describe call should === the stuff needed to create that thing declaratively.

CDK is an amazing project, their high level constructs are making AWS SAM / Serverless framework / Amplify seem complex. With a line of code I get a best-practice opinionated VPC, an ECS cluster, a Fargate task with an ALB. (off topic - be careful - always ensure tasks return 200 OK on a GET / or it will thrash for hours, as others commented below, it's a known bug, sadly I knew about it only after wasting hours on troubleshooting it)

So I agree perhaps CFN has native issues (speed, troubleshooting) but don't hate CDK just because it uses CFN in the back.

So if you have to choose between CloudFormation or Terraform, I'd choose CDK.