6 ms·

I think this hits on why these types of problems are potentially bad. You could be the world's worst software engineer, but if you'd taken a graph theory course

by defen 6y ago

I think this hits on why these types of problems are potentially bad. You could be the world's worst software engineer, but if you'd taken a graph theory course recently, you'd pattern match this, say "sure, can I use Matlab?" and be done in under 10 minutes. Or you could have tons of experience deploying robust production systems but have never happened to learn / need to use dynamic programming, in which case coming up with it in 45 minutes during an interview is not going to happen.

username90 6y ago
The junior and the senior aren't competing for the same job though, this just checks that you still remember the theory you learned in college. And no, just because you are senior doesn't mean that you get a free pass forgetting everything you learned in college. I haven't practiced problems like this in over 5 years and I still ace them.
- noitpmeder 6y ago
  /r/iamverysmart/
  - username90 6y ago
    What is your point? Companies wants to hire smart people which is why they have these interviews. This applies no matter what level people are at. "I forgot" isn't valid defense. All the people in these threads who says things like "I knew this but forgot" are really cringy.
    - Judgmentality 6y ago
      /r/woosh
      - username90 6y ago
        Do you think this is a good way to discuss things at HN?
        Judgmentality 6y ago
        I believe that HN needs more humor, not less - so yes.
    - noarchy 6y ago
      The point may be that many (if they're truly senior, not someone with 3-5 years in the industry) will not have used these theories in 10+ years. The real-world application is questionable.
      - username90 6y ago
        And my point is that I'd rather hire someone who didn't forget these things. When you learn something well you don't forget, it is like riding a bike. If you learned how to ride a bike 10 yards and then stopped and never did it again then you would forget how to do it, saying "I passed the bike riding test when I was 10, I don't need to do it again" isn't a good defense. I mean, why did you even go to college if you intended to just forget everything afterwards instead of learning the things properly for life? I'd rather not hire people who just do the work necessary to pass and get the degree and don't want to learn more.
        noarchy 6y ago
        I'd say it shows that for most day-to-day work in the software industry, a certain percentage of the CS material we learn is simply unnecessary. No one has ever asked me to re-implement well-known algorithms that are found in well-established libraries. There are, of course, people who do this, and they do need such a background. But they are likely outliers.
- defen 6y ago
  > this just checks that you still remember the theory you learned in college. Sure, but not everyone went to college or studied computer science / math. This seems like one of those problems that's really just testing a very specific type of preexisting knowledge.
  - username90 6y ago
    You'll get full score even if you don't know the matrix solution, just doing a memoized recursive one is enough. However if you had that specific knowledge then they still test whether they have the skills to apply esoteric knowledge correctly which is also very valuable. Anyway, Google no longer has this question. Once it gets known outside Google bans it from interviews. Sometimes people give banned questions but in general they don't and it is taken into account. I remember it being popular as a question 4 years ago, popular questions tend to leak quickly and get banned though.
    - Gunax 6y ago
      According to the blog post, the interviewers weren't even aware of the matrix solution until one candidate brought it up.
      - KnobbleMcKnees 6y ago
        I assume they all immediately handed in their letters of resignation and/or hired the candidate in as a principle engineer. Sarcasm aside, the very fact that they ban questions demonstrates how useless these types of questions really are. If you ban it because people might know it due to its popularity then what are you testing for? I thought it was for whether a candidate could solve the problem, but it appears to be to check which percentile of a special 'knowledge' club they belong to...
  - bakuninsbart 6y ago
    If you are an experienced programmer, how long does it take you to learn the handful or so algs/concepts you need for these kinds of problems? It'd probably 20-30 hours of learning, which is a reasonable expectation to ace interviews. - And it is not like you have to necessarily come up with a solution all by yourself, communicating your issues well, and the interviewer will probably help you, if you have an otherwise impressive résume it shouldn't pose a problem at all.
nitwit005 6y ago
I wouldn't be surprised if people occasionally re-create famous math problems, given how many interview questions seem to get created these days.
kevincox 6y ago
If someone just pattern matched it I would give them a backup question. The point of these questions isn't seeing if they can solve it, it is seeing how they think about problems. I'm also not worried if they make a good solution, or even get a solution at all. But almost all candidates can start making progress, come up with some possible solutions and tell me about those solutions.

by defen 6y ago

username90 6y ago

The junior and the senior aren't competing for the same job though, this just checks that you still remember the theory you learned in college. And no, just because you are senior doesn't mean that you get a free pass forgetting everything you learned in college. I haven't practiced problems like this in over 5 years and I still ace them.

noitpmeder 6y ago
/r/iamverysmart/
- username90 6y ago
  What is your point? Companies wants to hire smart people which is why they have these interviews. This applies no matter what level people are at. "I forgot" isn't valid defense. All the people in these threads who says things like "I knew this but forgot" are really cringy.
  - Judgmentality 6y ago
    /r/woosh
    - username90 6y ago
      Do you think this is a good way to discuss things at HN?
      - Judgmentality 6y ago
        I believe that HN needs more humor, not less - so yes.
  - noarchy 6y ago
    The point may be that many (if they're truly senior, not someone with 3-5 years in the industry) will not have used these theories in 10+ years. The real-world application is questionable.
    - username90 6y ago
      And my point is that I'd rather hire someone who didn't forget these things. When you learn something well you don't forget, it is like riding a bike. If you learned how to ride a bike 10 yards and then stopped and never did it again then you would forget how to do it, saying "I passed the bike riding test when I was 10, I don't need to do it again" isn't a good defense. I mean, why did you even go to college if you intended to just forget everything afterwards instead of learning the things properly for life? I'd rather not hire people who just do the work necessary to pass and get the degree and don't want to learn more.
      - noarchy 6y ago
        I'd say it shows that for most day-to-day work in the software industry, a certain percentage of the CS material we learn is simply unnecessary. No one has ever asked me to re-implement well-known algorithms that are found in well-established libraries. There are, of course, people who do this, and they do need such a background. But they are likely outliers.
defen 6y ago
> this just checks that you still remember the theory you learned in college. Sure, but not everyone went to college or studied computer science / math. This seems like one of those problems that's really just testing a very specific type of preexisting knowledge.
- username90 6y ago
  You'll get full score even if you don't know the matrix solution, just doing a memoized recursive one is enough. However if you had that specific knowledge then they still test whether they have the skills to apply esoteric knowledge correctly which is also very valuable. Anyway, Google no longer has this question. Once it gets known outside Google bans it from interviews. Sometimes people give banned questions but in general they don't and it is taken into account. I remember it being popular as a question 4 years ago, popular questions tend to leak quickly and get banned though.
  - Gunax 6y ago
    According to the blog post, the interviewers weren't even aware of the matrix solution until one candidate brought it up.
    - KnobbleMcKnees 6y ago
      I assume they all immediately handed in their letters of resignation and/or hired the candidate in as a principle engineer. Sarcasm aside, the very fact that they ban questions demonstrates how useless these types of questions really are. If you ban it because people might know it due to its popularity then what are you testing for? I thought it was for whether a candidate could solve the problem, but it appears to be to check which percentile of a special 'knowledge' club they belong to...
- bakuninsbart 6y ago
  If you are an experienced programmer, how long does it take you to learn the handful or so algs/concepts you need for these kinds of problems? It'd probably 20-30 hours of learning, which is a reasonable expectation to ace interviews. - And it is not like you have to necessarily come up with a solution all by yourself, communicating your issues well, and the interviewer will probably help you, if you have an otherwise impressive résume it shouldn't pose a problem at all.

nitwit005 6y ago

I wouldn't be surprised if people occasionally re-create famous math problems, given how many interview questions seem to get created these days.

kevincox 6y ago

If someone just pattern matched it I would give them a backup question. The point of these questions isn't seeing if they can solve it, it is seeing how they think about problems. I'm also not worried if they make a good solution, or even get a solution at all. But almost all candidates can start making progress, come up with some possible solutions and tell me about those solutions.