Yeah JSON/YAML is (mostly) great for data that needs to be parseable by machines and humans but trying to make a language out of it is horrible. Raw HCL2/Terra

Yeah JSON/YAML is (mostly) great for data that needs to be parseable by machines and humans but trying to make a language out of it is horrible. Raw HCL2/Terraform is marginally better IMO with being able to pass around more complex structs and function calls that don't have to be expressed as JSON dicts, but still remaining declarative to be able to create a dependency graph internally. All of this is why CDK now exists to be able to express these things as TypeScript or Python and spit out the corresponding CFN or TF. It's also worth noting that AWS added support for additional providers a while back so the CustomResource+Lambda you're describing isn't the only way to interact with non-AWS APIs. I'm actually curious what you're using - you've shit all over a bunch of things without providing any real alternative.