As organizations grow, Terraform codebases often grow with them—across teams, environments, accounts, and regions. What begins as a clean and modular setup can quickly become difficult to manage, duplicate, and evolve. This talk explores how to design an evolutionary Infrastructure as Code (IaC) architecture that scales without sacrificing clarity or autonomy. Using Terramate as an orchestration and structuring layer, we will examine practical patterns for organizing Terraform stacks, managing dependencies, and enabling multi-environment consistency.