DevOps/CloudBackendGeneralTable-stakes
Linux
Also written as Unix
An open-source operating system that runs the vast majority of servers, cloud infrastructure, and containers — comfort with its command line is assumed baseline for most backend and DevOps work, even when the day-to-day IDE is on Windows or Mac.
Think of it like
Like knowing how to drive a manual transmission — most day-to-day driving might be automatic (a GUI, an IDE), but production servers rarely come with one.
Junior or senior?
Junior sounds like
Says 'I've used Linux' with no further detail.
Senior sounds like
Is comfortable on the command line — permissions, processes, logs — under real pressure.
Ask them
“Walk me through how you'd track down what's eating memory or CPU on a Linux server, without a GUI.”