Terraform Best Practices: Infrastructure as Code in 2025

Terraform has become the de facto standard for Infrastructure as Code (IaC), enabling organizations to define, provision, and manage cloud infrastructure efficiently. This comprehensive guide covers the latest best practices for writing maintainable, scalable Terraform code in 2025.

Introduction to Terraform Best Practices

As infrastructure grows in complexity, following best practices becomes crucial for maintaining reliability, security, and efficiency. Modern DevOps engineers rely on these guidelines to write Terraform code that is:

• Maintainable across teams and over time
• Secure by default
• Efficient in execution
• Scalable as your infrastructure grows
• Collaboration-friendly

Core Principles

Before diving into specific practices, let's establish the core principles that guide Terraform best practices:

1. Declarative over Imperative: Let Terraform determine the execution plan
2. Modularity: Break down infrastructure into reusable components
3. Version Control: Treat infrastructure code like application code
4. Immutable Infrastructure: Replace rather than modify existing resources
5. Least Privilege: Grant only necessary permissions

These principles align with broader cloud security best practices and complement containerized infrastructure management approaches like Kubernetes.