nanog mailing list archives

Re: questions asked during network engineer interview


From: Michael Thomas <mike () mtcc com>
Date: Tue, 14 Jul 2020 13:27:15 -0700


On 7/14/20 1:14 PM, Matthew Petach wrote:


On Tue, Jul 14, 2020, 11:00 Ahmed elBorno <amaged () gmail com <mailto:amaged () gmail com>> wrote:

    15 years ago, I applied to a network admin role at Google, it was
    for their corporate office, not even the production network.

    I had less than two years experience.

    The interviewer asked me:
    [...]
    2) If we had a 1GB file that we need to transfer between America
    and Europe, how much time do we need, knowing that we start with a
    TCP size of X?



I *love* questions like that, because I can immediately respond back with "well, that depends; did your sysadmin configure rfc1323 extension support in your TCP stack?  Is SACK enabled?  What about window scaling?  Does your OS do dynamic buffer tuning for TCP, or are the values locked in at start time?"

Depending on how the interviewer responds gives me a pretty good idea how much clue the people I'd be working with have, and how well they work collaboratively even with people they don't really know.  If they respond well on their feet, and give me better inputs, I respond with a better answer.

If they say "It doesn't matter", then I respond by saying "See, that's why things aren't working so well for you here; you don't really understand how far down the rabbit hole goes", and respectfully ask to end the interview before we waste any more of each other's time.

This is the generic problem with interviewing is that people seem to believe they are born with a god given innate ability to interview people. They ask a generic question, and are surprised and often offended that they get an "it depends" and "please clarify XYZ". Interviewing is *hard* and doing a semblance of a good interview for a candidate is time consuming, so most people just punt with stupid unthoughtful questions where they think that all of the requirements are perfectly clear. Your answer *should* impress them, but I doubt that's the case in general.

Mike


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