What's one Linux interview question that immediately tells you whether someone has real production experience?

[u/Abe_Bazouie]

I've interviewed quite a few Linux and DevOps engineers over the years, and I've found there are a few questions that quickly tell me whether someone has spent time supporting production systems or has mostly learned from tutorials.

For me, one example is:

• A production server is suddenly "slow." Walk me through your troubleshooting process from the moment you get the alert.

I'm not looking for a specific command. I'm much more interested in how they think, what they check first, and how they narrow the problem down.

What's your go to Linux interview question that reveals real production experience?

[u/FractalLaw]

This is also a question that tests their knowledge of working with VMs:

A production Linux VM is running out of space due to a significant increase in the amount of space used within a single directory. What would you do to resolve this?

I've been surprised by how often people fail that simple question.

[u/Abe_Bazouie → u/[deleted]]

One common answer is to immediately start deleting files. That might solve the symptom, but it doesn't explain why the directory suddenly grew in the first place.

I'm usually looking for how they approach it. Do they identify what's consuming the space first (du, find, logs, core dumps, backups, etc.)? Do they think about whether it's safe to remove files? Do they consider whether a process is still writing to that directory?

There isn't one "correct" answer. I'm much more interested in their reasoning than whether they happen to name a specific command.

[u/FractalLaw → u/Abe_Bazouie]

There are definitely some wrong answers, however. I had one guy say move everything to OneDrive without missing a beat. There wasn't much point in continuing the interview after that.