Kubernetes Operator Development overview

Building custom Kubernetes operators using controller-runtime, kubebuilder, or operator-sdk. Covers the reconciliation loop pattern, custom resource definition design, status subresource management, finalizers, owner references, leader election, and webhook implementation (validating, mutating, converting). Includes testing strategies (envtest, integration tests against kind clusters) and operational concerns (graceful shutdown, metrics, health probes, RBAC least-privilege).