Pulumi vs Terraform

The fundamental difference is the language model. Terraform uses HCL (HashiCorp Configuration Language), a declarative DSL purpose-built for infrastructure — readable but limited in expressiveness. Pulumi lets you write infrastructure in general-purpose languages like TypeScript, Python, Go, C#, and Java, meaning you get loops, conditionals, functions, classes, and the full power of your existing language ecosystem. Both tools are declarative in intent (you describe desired state), but Pulumi expresses that state in real code rather than configuration files. This makes Pulumi especially powerful for teams with complex, dynamic infrastructure requirements, while Terraform's HCL remains simpler for straightforward, static configurations.

For most greenfield projects, the decision comes down to two factors: team language preference and existing ecosystem. If your team is already strong in TypeScript or Python and you want type safety, reusable component libraries, and unit-testable infrastructure code, Pulumi is the better choice. If your team has no strong language preference, is hiring ops-focused engineers who know HCL, or needs to integrate with a large Terraform provider ecosystem (1,000+ providers via the Terraform Registry), Terraform (or OpenTofu) is the safer default. In 2026, both tools are production-mature. The real question is whether you want infrastructure-as-code or infrastructure-as-configuration.

Yes. Pulumi has a bridge layer (pulumi-terraform-bridge) that wraps most Terraform providers and makes them usable in Pulumi programs. This means the 1,000+ providers available in the Terraform Registry — AWS, Azure, GCP, Datadog, Cloudflare, and virtually every SaaS tool — are accessible from Pulumi code. Pulumi also has its own native providers (AWS Native, Azure Native, Kubernetes) generated directly from cloud provider API specs, which are typically more complete and up-to-date than Terraform's equivalents. So Pulumi has full provider coverage without sacrificing compatibility.

Both tools store infrastructure state as a snapshot of your deployed resources. Terraform stores state in a flat JSON file (terraform.tfstate), which you must manage yourself — typically by pushing it to remote backends like S3+DynamoDB, GCS, or Terraform Cloud. Pulumi stores state either in Pulumi Cloud (hosted, free tier available) or in self-managed backends (S3, Azure Blob, GCS, local filesystem). Pulumi Cloud provides additional features like deployment history, drift detection UI, audit logs, and team access controls built in. With Terraform, those features require Terraform Cloud/Enterprise or custom tooling. For teams that want zero state management overhead, Pulumi Cloud has a clear advantage.

Yes — Pulumi provides a conversion tool (pulumi convert --from terraform) that translates HCL into your target language (TypeScript, Python, Go, or C#). For existing infrastructure, Pulumi's import command (pulumi import) reads live cloud resources and generates both the state entry and the corresponding code, so you don't need to recreate resources. The migration path is typically: (1) convert HCL to Pulumi code using the converter, (2) import existing state using pulumi state import or a batch import script, (3) run pulumi preview to verify no unintended changes, (4) gradually migrate stacks team by team. Most teams complete a full migration in 2–8 weeks depending on stack complexity.