Hands-on across all three container platforms: Amazon ECS (task definitions, EC2, Service Connect, ALB/WAF), Amazon EKS (Kubernetes, Helm, operators, NetworkPolicies, Ingress), and Red Hat OpenShift (self-managed on EC2; SCCs, Routes, BuildConfigs/Tekton, internal registry/Quay). DevSecOps toolchain / secure SDLC — CI/CD (GitLab/Tekton/Argo CD), SAST/DAST/SCA/IaC scanning, SBOM, image signing/scanning (Quay/Clair/ACS), secrets management (Vault/External Secrets), policy-as-code.