Deleting an ArgoCD Application doesn't delete deployed resources — you need a finalizer

After testing ArgoCD Capability on EKS, I ran kubectl delete application guestbook -n argocd expecting everything to clean up. The Application CR was gone, but the deployed Pod and Service were still running.

To cascade-delete deployed resources when removing an Application, you need a finalizer:

apiVersion: argoproj.io/v1alpha1
kind: Application
metadata:
  name: guestbook
  namespace: argocd
  finalizers:
    - resources-finalizer.argocd.argoproj.io
spec:
  # ...

Without it, only the Application CR gets deleted and deployed resources become orphaned. Note that syncPolicy.automated.prune: true only removes stale resources during sync—it has nothing to do with Application deletion. Even for testing, adding the finalizer saves cleanup headaches.