Explain what happens, at the OS level, between typing a command and seeing
output — processes, memory, scheduling, I/O, all of it.
Read a "server is slow" incident and know which Linux tool answers which
question (CPU? memory? disk? network?) instead of guessing.
Work the Linux command line fluently: navigate, search, process text,
manage files and permissions, and write a shell script that won't
embarrass you.
Explain what a container actually is (not "a lightweight VM" — the real
mechanism) and build, run, and debug one with Docker.
Read and reason about a Kubernetes manifest, understand what each
component of the cluster is doing, and diagnose why a pod won't start.
Connect an incident, a slow deploy, or a cost spike back to the specific
OS/Linux/container concept causing it — the skill that actually
separates "knows the commands" from "understands the system."
Know, for every topic, one real, well-documented incident or system where
it mattered — because concepts stick when they're attached to a story.
