Stairway to GitOps: Scaling Flux at Morgan Stanley

Morgan Stanley's platform engineers share a five-year journey scaling Flux-based GitOps across 500+ clusters, 2,000+ nodes, and tens of thousands of Flux resources. Starting from push-based CI/CD pipelines plagued by configuration drift and fragile recovery, they built a self-service onboarding platform leveraging Flux's RBAC-based multi-tenancy. At scale, they tuned reconciliation intervals, controller concurrency, and resource limits, and migrated from a self-hosted Git provider to S3 buckets for high availability. Observability was addressed via centralized Grafana dashboards extended with kube-state-metrics and Flux's Notification Controller. Future plans include Flux sharding, OCI artifacts as the primary source, and progressive delivery with Flagger.