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Dark Motives and Elective Use of Brainteaser Interview Questions

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Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#231
post #122
post #7

As someone who does both a lot of interviewing (at Google) and gives a lot of advice on interviewing to people just starting out, this rhymes with my intuition about why some people get into interviews: even without the use of brainteasers (which, for the record, are not used at Google), the interview process is hard . People rarely come out of it without at least a twinge of frustration of humiliation. I'm not immun…

> (which, for the record, are not used at Google) I interviewed maybe 3 or 4 years ago at Google. Definitely got some questions that were not remotely programming related, but were just hard problems that probably were awesome if you already knew the answer. I recall one was something along the lines of "You're making a bet in the final round of Jeopardy. Presume that your opponent is going to bet optimally given you…

I had a similar teaser question in an interview for a senior technical role which went something like: given a function that has a uniform distribution over N, how to create a new uniform distribution over N+k. I recalled the general idea/theory of building new distributions from old and felt confident I could find the answer with general resources (textbooks I had at my desk or a quick search). The (fairly junior) interviewer didn't recognize the idea and kept trying to push me towards a specific answer. I looked it up after the interview -- the problem is apparently well known in CS circles (it was not for a CS role) and was something I could look up in 3 minutes. I did not get the role.

Arrogant? Maybe I am, a little, sure. But I don't spend my days remembers every minute detail of every technical documentation I've come across -- I can't remember everything! What I _do_ instead is remember _how to recall_ technical items in specific contexts to quickly refresh and remind myself when the time comes.

I don't come across _too_ many arrogant or clueless interviewers, but when I do I am genuinely surprised.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#233
post #7

As someone who does both a lot of interviewing (at Google) and gives a lot of advice on interviewing to people just starting out, this rhymes with my intuition about why some people get into interviews: even without the use of brainteasers (which, for the record, are not used at Google), the interview process is hard . People rarely come out of it without at least a twinge of frustration of humiliation. I'm not immun…

> I have a pet theory that when people interview they bring this buried frustration into the room with them and use the interviewing process to play the part of the people they feel humiliated them. I think it's possible--but there was an experiment someone ran a few years ago with a guy applying to jobs in both software development and management (while qualified for both and resumes optimized for each). One of the…

> and there's more genuine fear of hiring someone who can't fizzbuzz.

I always hear this fear proclaimed but have never heard an actual story of a candidate failing to fizzbuzz, would love to hear an anecdote or two from anyone who has one.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#234
post #44
post #5

The single most effective interview question I ask: "What do you want to do?". I drill down on that to a granulator level as I try to make sure the tasks, duties and overall position matches what the candidate really wants for themselves. Its followed-up with a "How would you do it?", again persisting in the discussion (not interrogation) until we both are comfortable with the sensibility and symmetry of the answers.

If you think anyone 'really' wants to build your shitty CRUD app then you are deluding yourself. Do you 'really' love your job? Would you do it for free?

Yes, I would. Probably not for 40 hours a week, but I would.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#235

Earlier quoted context omitted.

> I have a pet theory that when people interview they bring this buried frustration into the room with them and use the interviewing process to play the part of the people they feel humiliated them. I think it's possible--but there was an experiment someone ran a few years ago with a guy applying to jobs in both software development and management (while qualified for both and resumes optimized for each). One of the…

> and there's more genuine fear of hiring someone who can't fizzbuzz. I always hear this fear proclaimed but have never heard an actual story of a candidate failing to fizzbuzz, would love to hear an anecdote or two from anyone who has one.

Not a candidate, someone we had already hired through an agency. Two someone’s actually. Never again.

They were great people, but couldn’t distinguish a string from an int.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#236

I recently interviewed at Apple and one interviewer caused me to decide to never work there. I was put into a conference room and had 8 people over 6 hours come in and interview me one after another. Each person asked me about my background and then jumped into a whiteboard coding problem. Most of the interviewers were understanding of the fact that writing code on a whiteboard is nothing like writing code on a compu…

> and he replied "sometimes you will have to fix your code on the spot"

You should have told him that "every time, you get to use a calculator". If I managed interviews, I'd have 1 person interview 1 person in a full-technical interview, without the personal questions, with 3 additional interviewers watching behind a one-way mirror. When the interview was over, I'd go in myself, and ask the candidate how well they thought they did, and how well they thought the interviewer did, with the 3 other interviewers still watching.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#237

I recently interviewed at Apple and one interviewer caused me to decide to never work there. I was put into a conference room and had 8 people over 6 hours come in and interview me one after another. Each person asked me about my background and then jumped into a whiteboard coding problem. Most of the interviewers were understanding of the fact that writing code on a whiteboard is nothing like writing code on a compu…

> Some jobs require performance under pressure, but programming is not one of them. In fact, programming under pressure is the leading cause of programming disasters. It's the exact opposite of what a rational employer should want.

> programming under pressure is the leading cause of programming disasters

I don't want to straw man you, but it seems like hiring someone who is demonstrably better at programming under pressure would mitigate the inevitable situations that force employees to program under pressure.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#238
post #118

Earlier quoted context omitted.

I interviewed at Google (back in 2005, mind you) and I remember being asked a couple brain teaser questions like how to estimate the number of windows in NYC. I will say that out of my loop, there were only 2 interviewers that came across as intentionally mean, the rest were genuinely wanting to see how I solved problems and understand what my thought process was, which is what most interviewers should be attempting…

Aren't the examples of brainteasers actually Fermi problems? Maybe they sound like brainteasers if asked without the appropriate context, but when you're doing a system design interview and you have to estimate your throughput or storage requirements, you're effectively solving a Fermi problem just like the one that asks you to estimate the number of windows in NYC.

I love the term "Fermi problem", because the origin is, of course, the Fermi paradox. The idea that multiplying a series of uncertainties together does something other than blow your error range out is such a weird idea.

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#239
post #235

Earlier quoted context omitted.

> and there's more genuine fear of hiring someone who can't fizzbuzz. I always hear this fear proclaimed but have never heard an actual story of a candidate failing to fizzbuzz, would love to hear an anecdote or two from anyone who has one.

Not a candidate, someone we had already hired through an agency. Two someone’s actually. Never again. They were great people, but couldn’t distinguish a string from an int.

That's pretty crazy, how do these people exist and get jobs? What kind of development were they supposed to be doing?

Re: Dark Motives and Elective Use of Brainteaser Interview Questions

#240
A Fermi problem is not a brain teaser in the colloquial sense, it's more of an approximation game. If you looked up an answer a week ago and memorized it, then regurgitated it, you'd still get the question "wrong". No one expects you to come up with the right number of windows, they expect you to get somewhere plausible from scratch.

Asking someone how many windows are in NYC is not fundamentally different than asking someone how many blades of grass are on a soccer field. You can know almost nothing and still arrive at the correct order of magnitude -- all it tests is someone's ability to do napkin math and break open-ended problems into manageable parts.

Is this the right thing to test? That depends on what you're hiring someone for.

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