Most ArgoCD tutorials start the same way: Deploy ArgoCD. Connect a Git repository. Create an Application. Done. But what happens when multiple teams start sharing the same Kubernetes cluster? Recently I was exploring a scenario where a single Amazon EKS cluster needed to support two different ArgoCD environments: A Custom ArgoCD instance for the Platform Team A Managed ArgoCD instance for Application Teams The Custom ArgoCD would manage infrastructure components such as: cert-manager external-dns monitoring ingress controllers While the Managed ArgoCD would be used by application teams to deploy: APIs frontends microservices business applications The challenge was figuring out how to keep both environments isolated while still sharing the same EKS cluster, Cognito User Pool, and AWS Application Load Balancer. At first, I thought: Why not just use a single ArgoCD instance? The more I thought about it, the more questions came up. How do we separate responsibilities? How do we avoid accidental changes?…