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What kind of work would this new applicant be doing? What product does your company make? > What is Big O notation, and why is it useful? Curious why you lea

What kind of work would this new applicant be doing? What product does your company make? > What is Big O notation, and why is it useful? Curious why you lead with this question? The rest of the top 11 questions are very Web dev and Javascript specific so that question sticks out. If people don't know the answer to it do you fault them for that?

bcherny 9y ago
It's a basic programming and communication skill. If someone doesn't know what it's called or what the syntax is that's fine. What's more important is the intuition: If I have program A: for (let i = 0; i < m; i++) {...} And program B: for (let i = 0; i < m; i++) { for (let j = 0; j < m; j++) {...} } Then A is more optimal than B, because A runs the loop m times, but B runs the loop m*m times. That's it - if an engineer can reason through that, it's enough to explain to an interviewer tradeoffs between a few possible algorithms that solve some question.
- flanbiscuit 9y ago
  Have you found that these questions have definitely helped you build a strong team? Has anyone ever passed your interview questions but failed as an actual employee? Just curious
  - bcherny 9y ago
    The "Concepts" and "Debugging" sections are very strong signals in my experience. "Coding" is much less useful IMO, but this blog post is to help you practice the sorts of questions that are asked in practice, rather than what I ask specifically.
    - flanbiscuit 9y ago
      yeah i figured it was a pick and choose what fits best. Thanks for sharing your list! These kind of interview questions get posted on HN a lot and there's always the same reaction.
eljimmy 9y ago
To me it's a good indicator of whether someone has a basic understanding of how to write efficient code. If you're hiring a mechanic, given the same pay request, who would you rather hire: (a) mechanic who can build a car that does 0-100 in 4 seconds or (b) mechanic who can build a car that does 0-100 in 10 seconds?
- deleted 9y ago
  [deleted]
zumu 9y ago
Interestingly enough, as a front end dev this was one of the few questions I agree with (though I'd present it differently). I wind up doing a ton of array/collection manipulation in my daily work, and I'd want to make sure any new members of the team could at least speak the same language.

bcherny 9y ago

It's a basic programming and communication skill. If someone doesn't know what it's called or what the syntax is that's fine. What's more important is the intuition: If I have program A: for (let i = 0; i < m; i++) {...} And program B: for (let i = 0; i < m; i++) { for (let j = 0; j < m; j++) {...} } Then A is more optimal than B, because A runs the loop m times, but B runs the loop m*m times. That's it - if an engineer can reason through that, it's enough to explain to an interviewer tradeoffs between a few possible algorithms that solve some question.

flanbiscuit 9y ago
Have you found that these questions have definitely helped you build a strong team? Has anyone ever passed your interview questions but failed as an actual employee? Just curious
- bcherny 9y ago
  The "Concepts" and "Debugging" sections are very strong signals in my experience. "Coding" is much less useful IMO, but this blog post is to help you practice the sorts of questions that are asked in practice, rather than what I ask specifically.
  - flanbiscuit 9y ago
    yeah i figured it was a pick and choose what fits best. Thanks for sharing your list! These kind of interview questions get posted on HN a lot and there's always the same reaction.

eljimmy 9y ago

To me it's a good indicator of whether someone has a basic understanding of how to write efficient code. If you're hiring a mechanic, given the same pay request, who would you rather hire: (a) mechanic who can build a car that does 0-100 in 4 seconds or (b) mechanic who can build a car that does 0-100 in 10 seconds?

deleted 9y ago
[deleted]

zumu 9y ago

Interestingly enough, as a front end dev this was one of the few questions I agree with (though I'd present it differently). I wind up doing a ton of array/collection manipulation in my daily work, and I'd want to make sure any new members of the team could at least speak the same language.