I've worked with Terraform extensively, including doing a lot of similar work (Reference Architectures, modules, AWS) over the past several years.

This was my first time using Pulumi, and it was very much a delight. There's clearly been a lot of thought and effort put into the plugins and overall developer experience.

For example, you can have Pulumi handle the Docker image builds for you - as well as the ECR repository logins and pushes. This means that your end users don't need to manually build images, log into ECR and push them - they just run `pulumi up` instead.