2.2. Managing Infrastructure as Code & Configuration

This section focuses on the core practice of managing your cloud environment programmatically. We will explore the various Infrastructure as Code (IaC) tools offered by AWS, best practices for multi-account governance, and advanced deployment techniques.

What breaks when infrastructure is managed manually? Everything — slowly. Consider a team of five engineers each creating resources through the console. Within weeks, production looks different from staging, security groups have unexplained rules, and nobody knows who changed what or why. Without IaC, your infrastructure becomes a snowflake: unique, fragile, and impossible to reproduce.

Think of IaC like a recipe versus cooking by feel. Both can produce a meal, but only the recipe guarantees the same result every time, in any kitchen, by any chef. CloudFormation, CDK, and Terraform are your recipes. They capture not just what exists, but why it exists — through comments, parameter descriptions, and version history.

The trade-off is upfront investment: writing templates takes longer than clicking through the console for a single resource. But what happens when you need to replicate that environment across 50 accounts? Or roll back a change that broke production? Or prove to an auditor exactly what changed and when? Manual processes fail at scale. IaC scales linearly.