Hacker News Board Hacker News, browsed like a classic message board
Live data from Hacker News

Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

news.ycombinator.com

Post reply on HN
Print view View original

111–120 of 206 posts

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#111

Post by HillaryBriss »

I have no info about whether Google/Facebook programmers can solve whiteboard questions easily so I expect this comment to be down voted but ...

I'm consistently surprised by the fact that, despite hiring programmers who are the world's most elite, Google's products and services are just kind of ... plain/average/boring. The products and services are far less amazing than Google's engineers.

It's like Google takes in geniuses but outputs kind of boring, standard, average quality products and services with a surprising number of problems and deficiencies.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#112

Post by aaomidi »

jfasi wrote: post #101
habosa wrote: post #36

I work at Google and no it's not easy for us either. I've heard many of my coworkers joke that if they went through the interview process again they'd probably fail. That said I see two kinds of interviewers. One kind (the good kind) takes a medium difficulty question and uses it to explore the candidate's coding, algorithms, communication, and problem solving skills. The other kind has a super hard question with a s…

I also work at Google and what mystifies me when I do interviews is just how consistently people manage to screw up even the medium difficulty questions. I used to love asking this question until it was banned: https://programmingpraxis.com/2012/01/20/knights-on-a-keypad... This is a great question because it has several levels of solutions: 1. A recursive solution that iterates over all sequences, exponential time a…

I mean I'm surprised you don't see why this question is plain stupid.

I've had to deal with an algorithm problem of this difficulty once in my entire work life and I was given a week time to go figure out the best way to go about this.

Your problem creates an unrealistic standard of a software developer. You don't get to see something like their coding quality which is a lot more important in a candidate than their ability to solve an arbitrary algorithms question. Especially since these algorithm quesstions are now being studied for the sake of interviews. Rather than to learn something.

It's shocking to me how many engineers I come across that think having an algorithms based interview actually gives them good results.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#113

Post by sadamznintern »

UncleMeat wrote: post #109
sadamznintern wrote: post #80

Earlier quoted context omitted.

That’s because the FB process explicitly optimizes for speed. I recently finished a loop where I solved 2 problems optimally in 2 interviews and 1 in the last one and I was rejected. The speed required makes me skeptical many people can solve these problems in the required time without luck of having seen similar problems before.

Did they tell you this? I feel like a lot of candidates think they nailed it when really they missed important things. I'm not sure I've ever had a candidate solve my question fully and optimally. This of course is nowhere near necessary to get a good score but I think that thinking "yep this is as good as it gets" is a common error. The hire rate is also super low at the majors so it could have also been noise.

Are you at FB?

One of them did tell me this after his round (said we got further than he thought we would), the other one explicitly said my solution was optimal and what he was looking for.

The 2 questions per interview "rule" is an open secret now among people that have interviewed there. I've never heard of someone who only answered 1 per round get a follow up or an offer.

*Also, they generally don't move onto a second question if they don't think the first one was good enough.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#114

Post by dekhn »

tootie wrote: post #100
dekhn wrote: post #2

I work for Google and have never been good at the "Here's an NP-hard problem you haven't heard of, write correct code for nlogn solution on whiteboard in language of choice" question. I had to train extensively (reading CLR, practicing) to be able to pass. However, large numbers of engineers at Google are very good at solving whiteboard questions. A lot of it comes from practice, a lot comes from knowing the common p…

Here's my real question: How often do you solve those kind of whiteboard problems in your daily work? Obviously, you'd never be forced to solve them in 45 minutes while being judged, but how often are you actually solving computer sciency kind of problems in general as opposed to solving more software engineering type of problems?

Almost never. I use a whiteboard, but only to draw architectural diagrams. Very few engineers at google actually do hardcore CS on a regular basis.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#115

Post by jasondclinton »

jfasi wrote: post #101
habosa wrote: post #36

I work at Google and no it's not easy for us either. I've heard many of my coworkers joke that if they went through the interview process again they'd probably fail. That said I see two kinds of interviewers. One kind (the good kind) takes a medium difficulty question and uses it to explore the candidate's coding, algorithms, communication, and problem solving skills. The other kind has a super hard question with a s…

I also work at Google and what mystifies me when I do interviews is just how consistently people manage to screw up even the medium difficulty questions. I used to love asking this question until it was banned: https://programmingpraxis.com/2012/01/20/knights-on-a-keypad... This is a great question because it has several levels of solutions: 1. A recursive solution that iterates over all sequences, exponential time a…

I wouldn't be able to answer this question in the time allotted and would heavily discount its signal if I were on the hiring committee with this question in the candidate's packet. It tests for algorithm memorization which is not a hiring signal.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#116

Post by driverdan »

jfasi wrote: post #12

I often do, both for fun and to prepare myself to give a question I'd like to use in an interview. The thing about interview questions at Google is there's a very fine line they need to walk: if they're too easy they give no useful information about the candidate, and if they're too hard they can never be solved in 45 minutes, again yielding no useful information. You also need to be able to provide some hints, becau…

> if they're too hard they can never be solved in 45 minutes, again yielding no useful information

I strongly disagree with the assertion that you get no useful information from an unsolved problem. The goal of giving a candidate a problem should not be to have them solve it. The goal should be to learn how they approach a problem, think it through, and work on solving it. Actually coming up with a solution is the least important part.

As an interviewer I've intentionally given people problems that would take more time than they have. I'm always upfront about it, making sure they know they may not solve it and that they should get as far as possible while explaining their choices.

As an interviewee I've been dinged for not solving problems. The reason why was because I spent most of my time talking through my approach and planning how I'd solve it. Without proper planning you get sloppy code, technical debt, and miss deadlines. Planning seems to be greatly undervalued in tech, especially in small startups.

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#118

Post by feverfew »

lynal wrote: post #32
Silhouette wrote: post #24

Earlier quoted context omitted.

Indeed, although it's not unheard of for mathematics lecturers at university to throw in a question within a twenty-question problem sheet for their course that is actually equivalent to some important unsolved problem, on the off chance that one of their students sees things in a totally new way and makes a ground-breaking discovery. Solving something NP-hard in linearithmic time would certainly qualify...

Do you have a cite/example of a lecturer doing that on an exam? Are there any examples where that has been successful? I had never heard of that happening! It would be extremely cool if it ever worked.

A teacher of mine, who studied maths at Oxford, was given a problem sheet on his first day and was told to finish by the time of his first tutorial. He made no progress and was reduced to tears as he thought he was incapable at Oxford. Turns out, he was given a set of unsolved problems on purpose :)

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#119

Post by pcwalton »

jfasi wrote: post #101
habosa wrote: post #36

I work at Google and no it's not easy for us either. I've heard many of my coworkers joke that if they went through the interview process again they'd probably fail. That said I see two kinds of interviewers. One kind (the good kind) takes a medium difficulty question and uses it to explore the candidate's coding, algorithms, communication, and problem solving skills. The other kind has a super hard question with a s…

I also work at Google and what mystifies me when I do interviews is just how consistently people manage to screw up even the medium difficulty questions. I used to love asking this question until it was banned: https://programmingpraxis.com/2012/01/20/knights-on-a-keypad... This is a great question because it has several levels of solutions: 1. A recursive solution that iterates over all sequences, exponential time a…

> I kinda want to open this up to the HN comments section, because this does not strike me as a brutally difficult problem, but the rate at which people fell on their faces when presented with this question suggests either something about our interview process or about the candidates we interview.

Because whiteboard coding is stressful and hard. I still kick myself for almost failing to get a basic sorting question right back in 2009, because the interviewer disguised it as a question about horse racing and it was interview 8 at the end of the day. (I still ended up getting an offer, but I turned it down.)

Re: Ask HN: Can engineers from Google or Facebook solve whiteboard questions easily?

#120

Post by smt88 »

sadamznintern wrote: post #84
HugoDaniel wrote: post #53

Yes because they only hire the absolute best

Top 1% of intelligence

Intelligence is hard to define. There's no scientific, widely-agreed-upon definition.

Even if there were, algorithm tests on whiteboards would be a poor test, because they also involve prior knowledge of the task and a very specific type of intelligence.

In my experience, social intelligence is a better predictor of success in any workplace, anyway.

Post reply on HN