Proven hands-on experience administering Docker and Kubernetes, including, cluster and workload operations; Namespace, RBAC, resource quota, ingress, storage, and network-policy management; Helm or equivalent package/deployment tooling; pod, node, container, certificate, networking, and deployment troubleshooting; and upgrade, patching, backup, recovery, scaling, and availability procedures. Experience with GitLab security capabilities or equivalent tools for static application security testing, dynamic application security testing, software composition analysis, secrets detection, container image scanning, infrastructure-as-code scanning, and SBOM generation and software supply-chain controls.