I guess it depends on what you mean by "under the hood". As far as I know it doesn't use Terraform during runtime but it uses the Terraform resources for genera

I guess it depends on what you mean by "under the hood". As far as I know it doesn't use Terraform during runtime but it uses the Terraform resources for generating language definitions. It has a lot of interoperability tools as well such as a "terraform bridge" and a tool that converts Terraform projects.