A short Linux exercise lets candidates demonstrate their command-line experience. Give the candidate a small set of files and ask them to work through a few everyday tasks. Listen to their choices, checks and explanations.

Prepare before the call

Ask the candidate to create a free Developer workspace in Runzivo, create a Linux sandbox and open its browser terminal before the interview. The sandbox quickstart covers setup. Check the terminal works before starting the exercise clock.

Developer includes 3,000 unit-minutes each month. CI and sandbox compute share that allowance. A running sandbox consumes allowance according to its size. Check the remaining balance and the current pricing before the call.

During your usual video call, ask the candidate to share their screen. Provide the same sample files, instructions and time limit to every candidate. Use synthetic logs and harmless scripts, without credentials or production data.

The 20-minute exercise

  1. Organize files. Create a directory under /workspace, move the supplied files into it and list what is there.
  2. Read a log. Find lines containing ERRORin the supplied log, count them and save the matching lines in a separate file.
  3. Run a script. Inspect the supplied script and its permissions. Make it executable, run it and explain the result.
  4. Inspect a process. Find the harmless process started for this exercise. Confirm its identity and process ID, then stop only that process safely.
  5. Check space. Inspect filesystem free space and the exercise directory’s disk usage. Explain what each measurement means.

Listen to the reasoning

Ask the candidate to explain their commands and how they check the outcome. Allow documentation and command help. Look for a clear approach, careful handling of files and processes, and an ability to recover from mistakes. Keep the task and expectations appropriate to the role. Use the exercise to discuss their approach and decisions.

Save the work and clean up

Copy any files you want to keep out of the sandbox before stopping or deleting it. Stopped sandbox compute is not billed. Files in /workspace survive a stop and start within the sandbox’s lifetime, but the expiry timer continues. Deleting or expiry removes temporary files. When finished, stop the sandbox and delete it once the work is saved.