My experience is only with the main AWS cloudformation based version of CDK, although there is also CDK for terraform, which supports any resource that terraform supports, although some of what I'm about to say is not applicable to that version.
What I like about CDK, is that you can write real code, and it supports a wide range of languages, although typescript is the best experience.
Provided that you don't use any of the `fromLookup` type functions, you can run and test the code without needing any actual credentials to your cloud provider.
CDK essentially complies your code into a cloudformation template, you can run the build without credentials, then deploy the built cloudformation template separately.
You don't need to worry about your terraform server crashing half way though a deployment, because cloudformation runs the actual deployment.