The recruitment interviews I host aren't pure practice. One of the stages I explicitly distinguish is called "engineering background check". Some do call it "the theoretical part" (because I ask candidates to explain a particular term to me), but it's only half-true. The purpose is not to verify candidates' memorization skills, because I don't care that much about encyclopedic kind of knowledge.
I have two goals there:
- to check whether the candidate was exposed (hands-on) to a specific challenge/experience in her/his past - e.g. for me it makes hell-of-a-difference whether someone had to check query's EXPLAIN output (and understands what it means in practical terms) or not
- to probe the "depth" of understanding & the "determination" in engineering curiosity - because it's the people who truly understand how things work under the hood, who can tackle the difference-making challenges
To achieve these goals, my initial questions frequently expand to the series of follow-ups:
- did you use it personally? where would you use it?
- what purpose does it serve? what's the cost to be paid?
- what would be the reasonable alternatives that could achieve the same effect?
- why can't I use Y (a deceptively similar, but not 1:1 equivalent) instead?
The wheel of (mis)fortune
Needless to say, some do well (present actual knowledge and a proper understanding), but many are quite far from impressing me - that's not surprising and I'm not going to mock anyone because of that. What I find ridiculous and incomprehensible is that fact, that many candidates who don't know the answer at all ... attempt to guess an answer - many of them don't even pretend they don't.
They thoughtlessly prefer any response over admitting they don't know something.
They seem entirely unaware of how it makes them look like. Let's face the facts: EVEN if they guess it right, this is not a TV quiz - you don't score points just because your answer was (by chance) correct. Questions are point checks that do probe your knowledge base. Good guesswork proves nothing (except that you've been lucky this time)!
What's more - who would like her/his team-mates "guessing" in the real-life problem-solving scenario? Where someone could make long-term meaningful technical/business decisions based on that answer? Everyone I know would rather appreciate an honest, straightforward "I don't know" - which is far less confusing, even if it may hurt your own ego a little bit (because no-one likes exposing her/his own deficiencies).
A recruitment interview is not a riddle competition. If X (a term I ask about) reminds you of something, but you're not certain - describe your thought association(s) and make it clear what you're SURE about (your context/exposure to the topic). Not knowing something is not a mortal sin. Being able to reason properly (as opposed to blind-guessing) & backing yourself up with facts & real experiences is a much better way to "score points" during the interview.