Infrastructure as Code: Terraform Patterns for Scalable Teams

In 2025, clicking buttons in a web console to create servers is unprofessional. It leaves no audit trail, it isn’t repeatable, and it breaks easily. Terraform is the industry standard for defining infrastructure as code.

The “Module” Sandwich

Do not write one giant main.tf file.

• Root Module: This defines your environment (e.g. prod/main.tf). It should only contain calls to other modules, passing in variables.
• Child Modules: These are reusable components (e.g. a standard s3-bucket module that enforces encryption and logging).

State Management

The terraform.state file is the keys to the kingdom.

• Remote Backend: Always store state in a locked S3 bucket or Terraform Cloud. Never on a laptop.
• State Locking: Use DynamoDB to ensure two engineers don’t try to update the infrastructure at the exact same moment.

CI/CD for Infra

Terraform should run in a pipeline (GitHub Actions).

1. Plan: On a Pull Request, run terraform plan. This shows exactly what will change. The team reviews this “Plan” like code.
2. Apply: On merge, terraform apply runs automatically.

This removes the “It worked on my machine” problem and gives you a perfect history of who changed what and when.

Is your infra messy? We refactor legacy setups into clean, modular Terraform. Contact our DevOps team.