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Google Tech Dev Guide

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Re: Google Tech Dev Guide

#71

Post by LouisSayers »

SamReidHughes wrote: post #64
m0zg wrote: post #51

Earlier quoted context omitted.

The problem here is the only non-bruteforce solution worth pursuing here involves DP with less-than-straightforward memoization rules, which the engineer is unlikely to actually use before or after the interview. So she has to waste a month studying _specifically for the interview_ and "refreshing" the skills she won't actually need on the job. It's like you're hiring a welder, but you want them to be good at jugglin…

Actually looking at their "brute force" solution, what I was referring to as brute force was their "greedy" algorithm, and the first optimization I came up with was the most optimal solution. I'd call that a very natural strategy to take -- try doing the words simultaneously instead of separately, and you see it. I don't even see that as DP. Not everybody will be as quick as me, but there are plenty of people that do…

If the skills were closely related to your job, then it doesn’t make sense that you’d need to refresh those skills - as you would have been applying them at your job...

Sounds like the skills are the useless things, not the work experience.

Re: Google Tech Dev Guide

#72

Post by jorblumesea »

lwansbrough wrote: post #2

"Given a string S and a set of words D, find the longest word in D that is a subsequence of S." Found under "Foundations of programming" -- this is exactly the type of problem I'd expect as question one under this section. When it's made by Googlers, that is. I make a lot of cool stuff day to day, and usually that requires a lot of code and knowledge about programming and topics that are rather advanced (currently I'…

These problems appear in every comp sci text book. For example: https://ebookclass.com/product/algorithms-4th-edition-4th-ed...

Chapter 5 has multiple pages devoted to string algos and problem solving with strings. https://algs4.cs.princeton.edu/50strings/

I don't think it's fair to blame Google for something that is fundamental for computer science students.

Re: Google Tech Dev Guide

#73

Post by cmrdporcupine »

intern4tional wrote: post #70
saulrh wrote: post #31

Earlier quoted context omitted.

Funny, I use this kind of thing all the time when I'm programming. I wrote a comment citing the pigeonhole principal to justify a test case not thirty minutes ago. And I'm not even doing anything wizardly or revolutionary, just improving some concurrency code in a random worker binary. As for your comment about "diversity of thought": These problems seem sterile when they're presented in the most general possible for…

You should include the fact that you work at Google (cause you do, and your response is not completely honest without that disclaimer). The parent's concern was that this is Google focused, and your response doesn't seem to disprove it in any way.

FWIW I work at Google and despise these kind of interview questions and think they have 0 relevancy to my job -- until they do, and then I look them up and research them -- which BTW is not a skill that this interview style tests for.

It's to the point where I've done interview training here twice and both times thrown up my hands and chosen not to interview, because I can't imagine giving an interview that I myself would just walk out of.

Re: Google Tech Dev Guide

#74

Post by nilkn »

saulrh wrote: post #31
lwansbrough wrote: post #2

"Given a string S and a set of words D, find the longest word in D that is a subsequence of S." Found under "Foundations of programming" -- this is exactly the type of problem I'd expect as question one under this section. When it's made by Googlers, that is. I make a lot of cool stuff day to day, and usually that requires a lot of code and knowledge about programming and topics that are rather advanced (currently I'…

Funny, I use this kind of thing all the time when I'm programming. I wrote a comment citing the pigeonhole principal to justify a test case not thirty minutes ago. And I'm not even doing anything wizardly or revolutionary, just improving some concurrency code in a random worker binary. As for your comment about "diversity of thought": These problems seem sterile when they're presented in the most general possible for…

To offer an alternative viewpoint:

I have a degree in pure mathematics from a highly ranked institution. I published research as an undergraduate. I went to multiple REUs. I participated in the Putnam and similar competitions. I read CLRS in 9th grade and didn't even bother taking an algorithms course in college. But even I find that these sorts of questions are more gatekeeping than anything else. That's not a perspective that I had when I was coming straight out of college.

The revelation for me came from working at a successful company that manages to hire great developers and build great teams without needing to ask these sorts of questions. It turns out that these sorts of problems are relatively rare in real software development work, and many developers who wouldn't necessarily ace them in 40 minutes under tightly controlled conditions can nevertheless come up with perfect solutions in a normal work context, should the problem actually arise.

The reality is this sort of question selects for personality just as much as it does programming ability. It selects for the sort of person who likes puzzles and brainteasers and spends a lot of time immersing themselves in that culture. It reinforces a lot of cultural stereotypes deeply embedded in the programming world.

There's also a lot of perspective to be gained by working outside of a major technology hub. If developers are rarer to come by, if you're in any sort of hiring position you realize just how careless it would be for you to throw away a candidate because they didn't ace this sort of question. It'd sort of be like a family without much food throwing out all their bread because they saw a fly land on it. Relying 100% on this sort of question reflects an overabundance of applicants more than it does any underlying universal quality in the interviewing strategy.

Beyond this, I think there's a little irony in your comment. You mention diff(1), but who's to say the author(s) of that tool would've necessarily solved this problem on the spot? You're actually making that assumption, which I find to be unjustified. There's an entire class of thinker and problem solver you're ignoring -- the deep thinkers, the great ponderers who soak their mind so thoroughly in a problem that they come out with something wonderful. But you might need to give them some space and a day or two.

Re: Google Tech Dev Guide

#75

Post by nradov »

seanmcdirmid wrote: post #67
saulrh wrote: post #31

Earlier quoted context omitted.

Funny, I use this kind of thing all the time when I'm programming. I wrote a comment citing the pigeonhole principal to justify a test case not thirty minutes ago. And I'm not even doing anything wizardly or revolutionary, just improving some concurrency code in a random worker binary. As for your comment about "diversity of thought": These problems seem sterile when they're presented in the most general possible for…

What does the above problem have to do with the pigeon hole principle? I’m all for CS foundations, I learned the pigeon hole principle as an undergrad, I never used it (in work or during my phd) and have since forgotten it, but I’m glad I did that. But the above problem....just feels like a Googly interview question, whether it is just diff or not. What really gets me riled up is that these companies don’t care about…

This seems related to Goodhart's law: "When a measure becomes a target, it ceases to be a good measure."

If the hiring process for some tech companies has become so dysfunctional that they actually consider brain teaser coding questions to be meaningful then we should expect that competitors with more results oriented hiring processes will eventually beat them in the market.

Re: Google Tech Dev Guide

#76

Post by seanmcdirmid »

nradov wrote: post #75
seanmcdirmid wrote: post #67

Earlier quoted context omitted.

What does the above problem have to do with the pigeon hole principle? I’m all for CS foundations, I learned the pigeon hole principle as an undergrad, I never used it (in work or during my phd) and have since forgotten it, but I’m glad I did that. But the above problem....just feels like a Googly interview question, whether it is just diff or not. What really gets me riled up is that these companies don’t care about…

This seems related to Goodhart's law: "When a measure becomes a target, it ceases to be a good measure." If the hiring process for some tech companies has become so dysfunctional that they actually consider brain teaser coding questions to be meaningful then we should expect that competitors with more results oriented hiring processes will eventually beat them in the market.

Perhaps the tenacity and work ethic needed to study a couple of months for an interview selects for people who would do the job well anyways? Maybe that is what it means to be Googly as a culture fit?

Anyways, practicing solving clever small programming problems at least isn’t boring (though I’m beginning to burn out on it), it reminds me of prepping for a high school or ACM programming contest. As long as it eliminates enough false positives, they’ll keep up with it.

It isn’t just if you can solve these problems, but can you also write straight lines of text on a white board? Also, do it while talking and and standing on one foot at the same time.

Re: Google Tech Dev Guide

#77

Post by kamaal »

lwansbrough wrote: post #2

"Given a string S and a set of words D, find the longest word in D that is a subsequence of S." Found under "Foundations of programming" -- this is exactly the type of problem I'd expect as question one under this section. When it's made by Googlers, that is. I make a lot of cool stuff day to day, and usually that requires a lot of code and knowledge about programming and topics that are rather advanced (currently I'…

>>If I came across this problem in my "Foundations of Programming" course equivalent when I first started to learn how to code, well I'd probably be enjoying my life as a woodworker right about now.

This. Many times.

When I first started learning programming. I picked up 'Learn C in 21 days' By Peter G. Aitken- Most other friends at college picked up more technically intense books.

I agree I took a good 2 months to get through the book. But I was the only one who travelled 2 months with the subject. By the end of the 2 months I had written several programs, gained a lot of confidence that I can code. Many people quit a lot early with their books.

These days when I want to learn to some thing new. I use the same approach. I pick the dumbest possible books and solve the dumbest possible problems. And then when Im months deep in with the subject, I move towards enlightenment.

Re: Google Tech Dev Guide

#78

Post by mav3rick »

sidlls wrote: post #68
mav3rick wrote: post #44

Earlier quoted context omitted.

And what if you don't have a standard library ? You're working on a new device, on a new language ?. Frameworks breed programmers with less adaptability, foundations breed problem solvers that can adapt across problems.

The fraction of engineers at Google to which these conditions apply is tiny. It's absolutely absurd to interview based on some fictitious need. The real reason Google interviews the way they do is not because they need a high bar. Their interviews are structured to preserve the egos of the interviewers and because, like the gaming industry, they can simply due to the sheer number of applicants.

"Their interviews are structured to preserve the egos of the interviewers "

You just stereotyped about 100k people. You have no idea about how many people work to make the interview questions as interviewee friendly as possible. You may hate the company but don't judge the people without knowing them.

Re: Google Tech Dev Guide

#79

Post by mav3rick »

sidlls wrote: post #68
mav3rick wrote: post #44

Earlier quoted context omitted.

And what if you don't have a standard library ? You're working on a new device, on a new language ?. Frameworks breed programmers with less adaptability, foundations breed problem solvers that can adapt across problems.

The fraction of engineers at Google to which these conditions apply is tiny. It's absolutely absurd to interview based on some fictitious need. The real reason Google interviews the way they do is not because they need a high bar. Their interviews are structured to preserve the egos of the interviewers and because, like the gaming industry, they can simply due to the sheer number of applicants.

Google's requirements also allow easy mobility between teams. If all I knew was one framework, I'd always have to prove myself again when I move teams. The hiring bar ensures that most candidates can adapt due to their strong CS base.

Re: Google Tech Dev Guide

#80

Post by dbt00 »

m0zg wrote: post #36
akanet wrote: post #5

Earlier quoted context omitted.

That's certainly your opinion, but the subsequence problem is a very general, abstract question that offers the candidate a number of ways to arrive a progressively better solution by following their intuitions. It's not the greatest interview question, but it's certainly not the worst. This website appears to be for people who already know how to code, and offers many different paths as well.

It doesn't. This seems like a typical Google interview question. If you didn't know how to solve it before the interview started, you aren't going to figure out anything other than a brute force solution in 45 minutes. And brute force solution will not get you a good grade in a tech interview at Google. It's idiotic: once you do get hired by Google, easily 80% of your work is copying one proto buffer into another, an…

As someone who's done a ton of tech interviewing for a blue chip silicon valley firm, viewing this as a homework problem to which there is one correct answer is exactly not what I'm looking for. I want to see your problem solving skills and I'm curious about your knowledge base, but if you don't know any of the specific techniques and/or don't get to the specific optimal solution I'm looking for I really don't give a shit.
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