CloudFormation and Terraform dependency
If your AWS resources management is done using both CloudFormation and Terraform, and if there is overlap/dependency between your team that uses CloudFormation and another team that uses Terraform, then do not just focus on your CloudFormation scripts.
Define the pre-conditions for your CloudFormation scripts.
- What are the AWS resources that should have been created prior to running your cloud formation scripts?
- What are the AWS resources that your cloud formation scripts is expected to create and hence the pre-condition is that these AWS resources should NOT have been created already with Terraform.
Know your code, but also know what the code expects as pre-conditions and whether these pre-conditions are met before starting the execution of the code.