Infrastructure‑as‑code in Azure has long been powerful but fundamentally stateless: ARM and Bicep deployments push resources, but Azure never truly remembers what belongs to what. That gap becomes painful in large, regulated, or multi‑team environments where lifecycle control, drift detection, and predictable updates are non‑negotiable. Azure Deployment Stacks change the model entirely by introducing a stateful, lifecycle‑aware deployment engine built directly into Azure Resource Manager. In this 45‑minute technical deep dive, we’ll dissect Deployment Stacks from the inside out—how they track resource ownership, enforce lifecycle rules, prevent accidental changes, and bring Terraform‑like state management natively into Azure. You’ll learn how to design stack‑based architectures for landing zones, shared services, and platform components, and how to use stacks to enforce guardrails, manage drift, and build defensible, auditable deployment workflows.