Handling Persistent Storage in Distributed environments (CSI).

Senior Docker engineering is about the intersection of Security, Scalability, and Operational Excellence.

At a senior level, you must understand the 'OCI' (Open Container Initiative) specifications. Docker is just a CLI tool that interacts with containerd, which then uses runc to spawn containers via Linux Kernel features. Security should be 'Shift Left'—scanning for vulnerabilities during the build and ensuring containers run as non-privileged users with restricted syscalls.