Provides Terraform module, testing, CI/CD, security and AWS stack-layout guidance layered with Provectus conventions (exact version pinning, required tags, ephemeral secrets). Use when working with Terraform - creating modules, writing tests (native test framework, Terratest), setting up CI/CD pipelines, reviewing configurations, choosing between testing approaches, debugging state issues, implementing security scanning (trivy, checkov), or making infrastructure-as-code architecture decisions. OpenTofu is largely compatible; verify feature floors. Does not cover application code, Kubernetes manifests, or CloudFormation/CDK.