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Google Hasn’t Changed Their Interview Questions

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Re: Google Hasn’t Changed Their Interview Questions

#11

Post by proksoup »

gaylemcd wrote: post #3
seunosewa wrote: post #2

Today I learned that Google's brain teasers are internally known as "estimation or market sizing questions"!

Asking "how would you estimate the number of cars sold in a year?" is not a brainteaser. It's an estimation / market sizing question. You can deduce a reasonable estimate from the population size and other assumptions. A brainteaser is something like "A man pushed his car to a hotel and lost his fortune. What happened?" That's a brainteaser -- and nothing Google would ask.

"How would you estimate the number of cars sold in a year?"

This boggles my mind. Where? For what purpose? Is the expectation that the candidate googles that question?

I would google lots of different things until I found some answers (car manufacturers sales reports from car magazines, news articles that may have the answer, literally for the phrase "number of cars sold in a year" etc, etc).

If you want me to talk through it, it's just mind numbing making asinine assumptions. Market sizing? Obvious assumptions? What?

I can't understand how anyone can say with a straight face that that question is straight forward and not ambiguous.

The ambiguity is what makes these google interview questions brain teasers, to me at least.

But that's probably the last item in a list of reasons why Google wouldn't hire me :)

Re: Google Hasn’t Changed Their Interview Questions

#12

Post by ChuckMcM »

gaylemcd wrote: post #3
seunosewa wrote: post #2

Today I learned that Google's brain teasers are internally known as "estimation or market sizing questions"!

Asking "how would you estimate the number of cars sold in a year?" is not a brainteaser. It's an estimation / market sizing question. You can deduce a reasonable estimate from the population size and other assumptions. A brainteaser is something like "A man pushed his car to a hotel and lost his fortune. What happened?" That's a brainteaser -- and nothing Google would ask.

I got asked the cars sold in a year in California question. I answered by saying I would look for a car that was new two years ago, and one that was new this year, and then difference the license plate numbers and divide by 2.

Took the interviewer a while but they finally figured it out.

Re: Google Hasn’t Changed Their Interview Questions

#13

Post by morpher »

I personally think that "estimation" questions (sometimes called "Fermi problems" since Enrico Fermi was famous for asking them) are a great way of gauging an individuals thought process.

They aren't about getting the right answer, but rather about seeing how one breaks down a seemingly difficult question into simpler pieces and determines what can be reasonably estimated. They really don't fall into the category of "brain teasers" which involve some sort of trick.

However, the statement that software developers are not asked these types of question is not universally true, nor should it be. In and SDE interview, I was asked an estimation question that was both interesting and relevant to the position (although I signed an NDA, so I'm not going to give specifics).

In my case, there were several pieces of required information that I realized I couldn't reasonably estimate on the spot, so I gave a description of how I could ballpark them from quick measurements.

Re: Google Hasn’t Changed Their Interview Questions

#14

Post by diminoten »

sharkweek wrote: post #6
ubercore wrote: post #5

My phone interview with Google had something I would probably describe as a brain teaser (which is probably why I didn't get a follow up interview). It was something along the lines of explaining how an insect in a bottle could jump out if the bottle was frictionless. Something like that. Anyway, I don't remember specifics well enough to make a strong statement, but I would argue that this isn't an absolute in either…

How did you answer that question? -- I honestly don't understand what possibly could be drawn from asking that. Deductive reasoning? Logical thought pattern? Creative thinking? Seems like there are a lot of better ways to find out if someone is capable of such things

Using a swimming technique to push off the air the bug could either gain momentum by using the bottle's sloped bottom as a kind of half-pipe, or start moving in a circular path until sufficient speed were built up that the bug would begin moving up the bottle's side.

Alternatively, the bug could fly out if it's that kind of bug. Or it could knock the bottle over by rocking it.

Clearly I'm Google material because of my "bug in frictionless jar" degree.

Re: Google Hasn’t Changed Their Interview Questions

#15

Post by diminoten »

vsla wrote: post #9

I aced the teaser back in college a s still didn't get the internship... What does that tell you?

That you didn't ace the teaser!

Or that there are other parts to a Google interview besides the teaser that can determine your employability at Google.

Re: Google Hasn’t Changed Their Interview Questions

#16

Post by gaylemcd »

proksoup wrote: post #11
gaylemcd wrote: post #3

Earlier quoted context omitted.

Asking "how would you estimate the number of cars sold in a year?" is not a brainteaser. It's an estimation / market sizing question. You can deduce a reasonable estimate from the population size and other assumptions. A brainteaser is something like "A man pushed his car to a hotel and lost his fortune. What happened?" That's a brainteaser -- and nothing Google would ask.

"How would you estimate the number of cars sold in a year?" This boggles my mind. Where? For what purpose? Is the expectation that the candidate googles that question? I would google lots of different things until I found some answers (car manufacturers sales reports from car magazines, news articles that may have the answer, literally for the phrase "number of cars sold in a year" etc, etc). If you want me to talk t…

It's okay that it's ambiguous. You can ask questions, like whether or not they're including motorcycles and buses.

The point is not to get the right answer. It's to deduce a reasonable answer that's in the right ballpark.

Re: Google Hasn’t Changed Their Interview Questions

#17

Post by yelnatz »

makerops wrote: post #7
sharkweek wrote: post #6

Earlier quoted context omitted.

How did you answer that question? -- I honestly don't understand what possibly could be drawn from asking that. Deductive reasoning? Logical thought pattern? Creative thinking? Seems like there are a lot of better ways to find out if someone is capable of such things

"Quit wasting my fucking time google-interviewer." "Correct. You're hired."

If only it was that easy.

Re: Google Hasn’t Changed Their Interview Questions

#18

Post by asnyder »

Sounds like she's still perpetuating the problem:

Software Engineering interviews will focus on your standard coding, algorithm, and system design questions...

Why are algorithm questions still being asked in a high-pressure environment? Very few people actually work on algorithms once hired and never in my experience has it actually been a good indicator of actual development competency. As DHH states: http://37signals.com/svn/posts/3071-why-we-dont-hire-program..., unless you're hiring someone to code algorithms it's not useful.

As a Director at AppNexus I've done my best to reverse this trend by asking what I consider competency questions. Such as "On a scale of 1-10, 1 being novice, 10 being creator of said technology, how would you rate yourself?" Then based on this answer I'll ask a question at that level. I find that most people screened don't actually know the basic fundamentals of the technologies they list.

After you've gotten the basics down you can then get into system-design, or thinking questions. In the case code analysis is necessary I think it's much better to present a sub-optimal pre-written function and ask the candidate what the function does, and whether and how it can be improved. In this way I know whether they understand code, and whether they're competent enough to improve.

The faster we move away from these algorithmic questions the better.

Re: Google Hasn’t Changed Their Interview Questions

#19

Post by yelnatz »

morpher wrote: post #13

I personally think that "estimation" questions (sometimes called "Fermi problems" since Enrico Fermi was famous for asking them) are a great way of gauging an individuals thought process. They aren't about getting the right answer, but rather about seeing how one breaks down a seemingly difficult question into simpler pieces and determines what can be reasonably estimated. They really don't fall into the category of…

How many golf balls can you fit in a bus?

How many plumbers in New York?

Re: Google Hasn’t Changed Their Interview Questions

#20

Post by token_female »

proksoup wrote: post #11
gaylemcd wrote: post #3

Earlier quoted context omitted.

Asking "how would you estimate the number of cars sold in a year?" is not a brainteaser. It's an estimation / market sizing question. You can deduce a reasonable estimate from the population size and other assumptions. A brainteaser is something like "A man pushed his car to a hotel and lost his fortune. What happened?" That's a brainteaser -- and nothing Google would ask.

"How would you estimate the number of cars sold in a year?" This boggles my mind. Where? For what purpose? Is the expectation that the candidate googles that question? I would google lots of different things until I found some answers (car manufacturers sales reports from car magazines, news articles that may have the answer, literally for the phrase "number of cars sold in a year" etc, etc). If you want me to talk t…

I think this does a good job of illustrating what a good answer to this kind of problem is and why it is not a stupid question to ask at an interview: http://what-if.xkcd.com/4/

> First, let’s start with wild ballpark approximations. This is an example of what might go through my head before I even pick up a calculator, when I’m just trying to get a sense of the quantities - the kind of calculation where 10, 1, and 0.1 are all close enough that we can consider them equal:

> I can pick up a mole (animal) and throw it.[Citation needed] Anything I can throw weighs one pound. One pound is one kilogram. The number 602,214,129,000,000,000,000,000 looks about twice as long as a trillion, which means it’s about a trillion trillion. I happen to remember that a trillion trillion kilograms is how much a planet weighs. [illustration showing that a trillion is visually approximately one half of one mole]

> … if anyone asks, I did not tell you it was ok to do math like this.

> That’s enough to tell us that we’re talking about pile of moles on the scale of planets. It’s a pretty rough estimate, though, since it could be off by a factor of thousands in either direction.

Anything general I could say has already been said in this thread and others (it's to see how you think about the problem, not about the answer, etc.), but for me it was seeing some examples like this one that finally made me get it.

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