Terraform Best Practices 2026: How Senior Engineers Write IaC

What Separates Senior from Junior Terraform

Junior: one big main.tf, hardcoded values. Senior: modules, remote state, workspaces, CI/CD for infrastructure.

1. Remote State

terraform {
  backend "s3" {
    bucket         = "mycompany-tfstate"
    key            = "production/terraform.tfstate"
    region         = "ap-south-1"
    encrypt        = true
    dynamodb_table = "terraform-state-lock"
  }
}

Without remote state: two engineers apply simultaneously, state diverges, infrastructure becomes unmanageable.

2. Module Structure

terraform-infra/
├── modules/vpc/
├── modules/eks/
├── modules/rds/
├── environments/dev/
└── environments/production/

Same modules, different variable values per environment.

3. Terraform in CI/CD

Run terraform fmt -check, terraform validate, terraform plan on every PR. Post plan output as PR comment so infrastructure changes get code review. terraform apply only on merge to main with approval. See Terraform Academy for complete IaC path.