The policy-as-code engine is the standout feature for us — being able to define OPA-based policies to control who can approve and apply Terraform changes has greatly improved our governance over AWS infrastructure. Stack management is also solid, making it easy to organize and track deployments across multiple environments. The pull request preview feature is a big workflow win: engineers can see a Terraform plan directly in their PR before merging, which catches issues early and speeds up code review.

Spacelift goes beyond the basics of managing the lifecycle of OpenTofu and other IaC tools by adding useful constructs like spaces, contexts, and integrations that make managing a large number of configurations a scalable process. The web user interface is basic, but gives easy access to all the key information One thing that really impressed me is the quality of the integration with GitHub repositories. Spacelift not only runs OpenTofu plans automatically for pushes and pull requests, but does so without any manual configurations or boilerplate workflows in the repositories. It also handles monorepos really well, only running plans only for stacks that are actually affected by changed files. And, it's possible to promote proposed changes all from within GitHub. The spacectl CLI is similarly well integrated, making it easy to integrate into local development workflows.

Lots of flexibility - integrate with your workflows without needing to change them. Great collaboration features like pull request previews, access levels, change approvals, and more.