This case study is an independent architecture design exercise developed to demonstrate enterprise-scale Policy-as-Code governance platform architecture for multi-subscription Azure environments. It was not associated with a production deployment. The scenario is based on the compliance governance requirements typical of organisations managing Azure infrastructure across multiple subscriptions and environments with automated enforcement, real-time remediation, and executive compliance reporting requirements. This study focuses on enterprise governance operations at scale — multi-subscription policy management, environment-aware initiative design, event-driven remediation orchestration, Azure Resource Graph compliance analytics, and Power BI executive reporting. Security scanning in IaC pipelines and deployment-time governance are covered in depth in the Security-as-Code & DevSecOps Governance case study.