TOPIC IAC
Infrastructure as Code managing infrastructure through machine-readable definition files
IN 10 SECONDS
Instead of clicking in a web console, you write configuration files (HCL for Terraform, YAML for CloudFormation, TypeScript for Pulumi) that declare your infrastructure. These files are version-controlled, code-reviewed, tested, and applied through automation. The cloud provider's API is the only interface — no manual steps.
GOTCHA Drift happens — someone edits a resource via the console, a script, or an auto-scaling event. Terraform will detect drift on the next `plan` and offer to revert it. That's a feature, not a bug.
HOW IaC CHANGES THE GAME
01 You write a config file describing a VPC, subnets, EC2 instances, and an RDS database.
02 CI runs `terraform plan` or `pulumi preview` in the PR for peer review.
03 Engine computes the diff between the current state (from state file) and the desired state (from config).
04 Apply executes the necessary API calls to converge real-world resources to the config.
POKE IT YOURSELF
terraform plan — preview changes before applying
pulumi preview — see what Pulumi would change
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