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Romulo Franca
Romulo Franca

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Terraform vs. Pulumi vs. Crossplane: Choosing the Right IaC Tool for Your Internal Developer Platform ๐Ÿš€

Infrastructure as Code (IaC) is at the heart of modern platform engineering, enabling teams to define, provision, and manage infrastructure in a repeatable and scalable way. When building an Internal Developer Platform (IDP)โ€”a self-service system that abstracts infrastructure complexities for developersโ€”choosing the right IaC tool can make or break your platform's success.

So, should you use Terraform, Pulumi, or Crossplane to power your IDP? Let's break it down. ๐Ÿ•ต๏ธโ€โ™‚๏ธ


๐Ÿ† The Contenders: Terraform, Pulumi, and Crossplane

1๏ธโƒฃ Terraform: The Industry Standard for IaC

Terraform, by HashiCorp, is the granddaddy of declarative IaC. It uses HCL (HashiCorp Configuration Language) and is loved for its mature ecosystem, large provider support, and battle-tested reliability.

Pros:

  • Huge community support and ecosystem ๐ŸŒŽ
  • Mature, stable, and widely adopted โœ…
  • State management with Terraform Cloud & backend options
  • Supports a vast number of providers (AWS, GCP, Azure, Kubernetes, etc.)
  • Well-suited for infrastructure teams managing shared resources

Cons:

  • Declarative-onlyโ€”not great for complex logic ๐Ÿ”„
  • State management overhead can be a pain
  • Writing HCL can feel restrictive for developers used to imperative programming

2๏ธโƒฃ Pulumi: IaC for Devs Who Love Code

Pulumi takes a code-first approach to IaC, allowing you to use programming languages like TypeScript, Python, Go, and C# instead of a declarative language.

Pros:

  • Leverages real programming languages for infrastructure ๐Ÿ’ป
  • Easier for developers to adopt (especially in an IDP setting)
  • No state file management (defaults to backend storage like AWS S3)
  • Great support for Kubernetes and cloud-native workloads

Cons:

  • Smaller ecosystem compared to Terraform
  • Less mature than Terraform, with a smaller community
  • Requires learning a new API even in familiar languages

3๏ธโƒฃ Crossplane: The Kubernetes-Native IaC Solution

Crossplane is a cloud-native control plane that extends Kubernetes to manage infrastructure using Kubernetes Custom Resource Definitions (CRDs). It brings GitOps-style infrastructure management to the table.

Pros:

  • Full Kubernetes integrationโ€”your infra is managed like any other K8s resource ๐Ÿ“ฆ
  • Eliminates the need for external state management
  • Policy-driven infrastructure provisioning ๐Ÿ›ก๏ธ
  • Multi-cloud support with a single API surface

Cons:

  • Requires deep Kubernetes knowledgeโ€”not ideal for non-K8s users ๐Ÿšง
  • Smaller ecosystem compared to Terraform
  • Can be overkill if your IDP doesnโ€™t revolve around Kubernetes

๐Ÿ”ฅ Terraform vs. Pulumi vs. Crossplane: Which One Wins for IDPs? ๐Ÿ

๐Ÿš€ Developer Experience (DX)

  • Pulumi wins for developers who want a familiar coding experience.
  • Terraform is okay, but HCL can feel clunky.
  • Crossplane is K8s-centric, which may or may not fit your developers' needs.

โš™๏ธ Integration with Kubernetes

  • Crossplane dominates hereโ€”itโ€™s built around Kubernetes.
  • Terraform and Pulumi can integrate with Kubernetes but require extra work.

๐Ÿ“ฆ Multi-Cloud & Multi-Provider Support

  • Terraform has the most providers (AWS, GCP, Azure, Kubernetes, etc.).
  • Pulumi supports many of the same providers but has a smaller ecosystem.
  • Crossplane is great for cloud-native multi-cloud but lacks the breadth of Terraform.

๐Ÿ”„ State Management & GitOps

  • Crossplane handles state natively with Kubernetes (no need for an external state store!).
  • Pulumi has backend storage options and doesnโ€™t require state management.
  • Terraform requires state management (Terraform Cloud, S3, Consul, etc.).

๐Ÿ—๏ธ Best Fit for Internal Developer Platforms

Feature Terraform Pulumi Crossplane
Best for Ops Teams โœ… โŒ โŒ
Best for Dev Teams โŒ โœ… โŒ
Best for K8s Users โŒ โœ… โœ…
Maturity & Stability โœ… ๐Ÿ”ธ ๐Ÿ”ธ
GitOps Friendly ๐Ÿ”ธ ๐Ÿ”ธ โœ…
  • Use Terraform if: You need a stable, widely adopted solution for traditional infra provisioning.
  • Use Pulumi if: You want an IDP that feels more natural for developers and supports multi-cloud.
  • Use Crossplane if: Your IDP is deeply Kubernetes-native and you want full GitOps integration.

๐ŸŽฏ Final Verdict: Choose Based on Your IDP Needs

Thereโ€™s no one-size-fits-all solution. The right tool depends on how your IDP is structured and who will be managing infrastructure:

  • For Ops-driven teams โ†’ Terraform
  • For Developer-friendly experience โ†’ Pulumi
  • For Kubernetes-native GitOps setups โ†’ Crossplane

If youโ€™re building an IDP, consider mixing Terraform for infrastructure provisioning and Crossplane for Kubernetes resource management. Or, if your developers love coding, Pulumi can bridge the gap between infra and app dev teams.

๐Ÿš€ Next Steps

โœ… Try out each tool in a proof-of-concept for your IDP.
โœ… Consider hybrid approachesโ€”many teams use Terraform + Crossplane or Pulumi + Terraform.
โœ… Embrace automation and GitOps to make infra changes seamless.

Which tool are you using for your IDP? Let me know in the comments! ๐Ÿ› ๏ธ๐Ÿ’ฌ

Top comments (1)

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alanwds profile image
Alan Wand

Great insights. Thanks for the content.