Enterprise adoption of GitHub Actions introduces governance and security challenges beyond basic CI/CD automation. In regulated environments, deployment platforms must prevent workflow bypass, eliminate long-lived credentials, and enforce scalable policy controls without slowing developers down. This session shares practical lessons learned while designing a governed deployment platform using GitHub Enterprise Cloud, reusable workflows, OIDC federation, AWS IAM, and environment protections. We will explore real-world challenges around deployment trust boundaries, workflow security, and policy enforcement in enterprise-scale CI/CD. Attendees will gain practical insights into balancing developer experience with secure deployment governance in modern cloud-native environments.