Dark Motives and Elective Use of Brainteaser Interview Questions

“I’d like to understand how you structure problems, we can do a different topic if you like?”

“With ~50M people capable of clicking ads, and assuming they click one ad a day at 20cnt CPC, it would be around 3.6bn. I think my assumptions are on the high side, but order of magnitude is probably correct”

If done well, solving a problem (not a brain teaser) together can yield insight in how people approach new challenges.

If I’m hiring for someone to do what they already know this indeed not a useful question. on the other hand, if I expect the role to tackle various business problems as well I’m not sure what would be a much better way to get a sense on this. (Specifically because I’d want to discuss a not-too-complex problem that is outside your usual area of expertise)

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 computer, and were helpful in pointing out simple mistakes that a compiler would have caught.

While writing code for the last interviewer I had to do some simple division. I came up with the wrong answer and told the interviewer that I wasn't sure if that was correct, and to let me know if it was incorrect. He blankly stared at me and said he wouldn't help me. Usually I would be able to do the division in my head, but after 6 hours of constant interviewing my brain was starting to turn into mush. I went on and finished the solution and he said that there was an issue but wouldn't tell me where. I asked if it was an issue with the division and he said yes. He still wouldn't tell me the answer, so I floundered for a bit while trying to remember how to do long division.

At one point I turned to him and said "I'm sorry this is taking me so long, it's been a very long day" and he replied "sometimes you will have to fix your code on the spot". It seemed like he was trying to see if I would crack under the pressure. Eventually I came up with the correct answer and was able to finish the problem, but it completely drained me.

I decided then that I never wanted to work with that person, or with other people like them.

Some jobs require performance under pressure, but programming is not one of them. The only thing that the interviewer was evaluating was my ability to do math problems in my head after being interviewed for 6 hours. Don't they have calculators at Apple? Or phones, perhaps?

> ...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.

Which is unfortunate. To measure something, it's necessary to test to the boundaries of its ability, which basically means crossing eventually into the realm of failure.

Too much of testing both in education and in job interviews is oriented to get a pass/fail result. Interviewers should understand that a good interview is not like this and should communicate this to the prospect: the goal is to measure your abilities and compare it to the needs of the position. Answering well for the most part, but not remembering some obscure academic topic or missing a particularly difficult part of a logic problem means that part of the interview helped find that boundary.

Honestly, if you answer 100% of the questions in the interview it means that they don't know how good you are, what they should pay you, or what you can expect to be challenged by in the job. They will want to know how much more they should offer and ask if they can take on much more difficult projects, but they don't know how much. That's an interview failure by the interviewers.

Maybe the correct stratagy is turn the tables and try to lighten the mood of the interview if a brainteaser is asked, and sort of shuck "oh one of these things? (laugh)...ok let's work this out together" and proceed to try to engage the interviewer with estimating the number of floors in an average building, the number of windows per story, and the number of buildings, all the time asking the interviewer what his estimates would be?

Like anything to prevent yourself from locking up and taking the damn thing too fucking seriously.

The reality is we are all going to interview, they are going to mostly suck, and you will almost certainly eventually be hired somewhere.

Well, let's be honest. The vast majority of jobs are just that: jobs. They're not something that anyone particularly wants to do; they're just willing to do it because it's better than the alternative.