Ask HN: What % of your job interviewees pass FizzBuzz type questions? • Hacker News Board

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#101

Post by chc » Fri, Sep 16, 2011, 10:30 PM UTC

wladh wrote: post #68

dlikhten wrote: post #47

Earlier quoted context omitted.

Give em a laptop. Those are a dime a dozen (we got a ton sitting around the office). Have em code in front of you. Hell I'd install any interpreter within reason to let em solve it.

It's not about how expensive a laptop is or isn't. If somebody can't master the basic syntax of the language so that they can write a very basic algorithm without syntax errors and in such a way that it would run on the first try, they can't be very productive. And fizzbuzz is really the rock-bottom of the simple algorithms. Even a linked-list library would be a very reasonable thing to ask (if we're talking about C…

I have a better grasp of the English language than the average college graduate, but I still make stupid errors even in the comfortable environment of a text editor. I might leave an article out, or I might miss a period, or I might write a homophone even though I know the correct spelling. As an editor, I've worked with a lot of professional writers — to a man, they all made mistakes as well. This is why I proofread anything important.

And that's under ideal conditions! Writing code on a whiteboard is so far from ideal for most people that keeping your variable names consistent is a challenge — balancing parentheses and brackets and keeping track of little dots is outright grueling, and doing all this during a job interview is enough to make even very competent programmers choke.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#102

Post by eropple » Fri, Sep 16, 2011, 10:35 PM UTC

aplusbi wrote: post #96

tzs wrote: post #93

Earlier quoted context omitted.

Interesting. I'd find the permutations one trickier, and yes I've encountered permutations in math and have been a programmer a long time). Here's why I'd find it tricky. There is an obvious recursive algorithm, but I'd be worried that if I gave that the interviewer would quibble about stack usage (although it is going to be linear in the number of items being permuted which should be OK most of the time). Thinking a…

Interestingly enough no one I've interviewed has every suggested lexicographical ordering although I have implemented it that way myself to see how hard it would be (answer: it's kind of hard). That said, C++'s standard library has a next_permutation function that returns the lexicographical next permutation of a pair of iterators (actually it does it in-place and returns a bool). If a candidate used that I'd allow i…

Given that I've been back in C++ mode for the last week, this is exactly what I was considering (using next_permutation). ;)

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#103

Post by aplusbi » Fri, Sep 16, 2011, 11:21 PM UTC

pp13 wrote: post #99

aplusbi wrote: post #88

Earlier quoted context omitted.

These questions aren't about "real world" situations, they are about problem solving and basic coding. Questions are good, as is a discussion on how and why these things should be implemented. For the split array problem I rarely ask for code (only when I think it will actually help the candidate), it's just a discussion. It usually goes something like this: Candidate: Well I can sort it first, then do a binary searc…

You should highlight, recent college graduates. If someone does get hired to your firm, I hope the "real world" problems are just as interesting. I actually like those type of algorithmic problems you highlighted. I am not sure, what it measures other than the recent graduate knew his/her data structures and read their MIT Algorithms books really well. Very few jobs do require knowing that fundamentals that in depth.…

I think the best programmers are ones who can utilize abstractions while at the same time understand what they are abstractions of. For example, someone who knows Django and SQL is probably a better programmer than someone who knows Django but doesn't understand what a relational database is.

While people might not need to write searching and sorting algorithms much any more, understanding the difference between an ordered map and a hash table can be crucial in many common "real world" scenarios.

I also have tried to stress that the answers to my algorithm questions are only part of the criteria in determining whether we hire someone or not. I brought them up because the OP asked specifically about coding questions, not hiring questions.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#104

Post by mattm » Sat, Sep 17, 2011, 1:56 AM UTC

ericb wrote: post #69

oscardelben wrote: post #20

Earlier quoted context omitted.

If you're considering remote employees or contractors I'd like to get in touch.

It is under consideration. If I can sell management on it (I'm senior dev here), I will be in touch.

Feel free to contact me as well if you get the ok on remote.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#105

Post by aplusbi » Sat, Sep 17, 2011, 2:42 AM UTC

pp13 wrote: post #98

aplusbi wrote: post #91

Earlier quoted context omitted.

Part of our interview process is having the candidate code-review some really bad code. The only problem with it is that it is biased against students/recent graduates. I'd say close to 90% of student/recent grad candidates do pretty poorly on the code review question.

What type of candidate are you looking for? Obviously recent graduates will not have that much coding experience and reading comprehension. Are you looking for someone to write new libraries from scratch? Who can implement new algorithms and data structures from nothing. Someone who can write new protocols and publish it to the team? Are you looking for someone who can read your code base? Just fix bugs? This one pro…

I work for a financial software company and we have a lot of projects so it depends, really. Recently we've been looking for some frontend Javascript developers the project I work on. The interviews we've been conducting have reflected that - mostly questions on things like JQuery/Moo Tools, having the candidate code stuff using AJAX, etc. "Real world" stuff in other words.

We often hire C++/C#/Python/Perl/Ruby/Objective-C/Java/etc (seriously, we use all those languages) to work on existing code bases. We work on Linux, VMS, Windows, iOS, and BlackBerry. We have plenty of "glue" code, frontend code and code that needs to deal with large amounts of data.

We don't expect recent graduates to have much coding experience. You seem to think that we have some strict checklist which is not the case at all. I really don't know where you got this idea. My initial comment was simply meant to answer the OPs question. I don't always ask those questions, I weight many things in my decision (including whether I think I conducted the interview well - sometimes it's clear that I've failed to properly describe the problem) and discuss the candidate with other people who have also interviewed them.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#106

Post by ericb » Sat, Sep 17, 2011, 3:38 AM UTC

dhimes wrote: post #15

ericb wrote: post #2

In the actual interview, I find that most give up after spitting out some pseudocode. About 40% have reasonable psuedo code that makes me think they'd get there (but these half-answers don't give me enough confidence to give them a thumbs up). Actual code that works (and running it from a terminal), we are seeing only about 15% tops maybe lower. We have started sending a fizzbuzz-ish question, a relatively easy css q…

The job has a lot of pros, but probably doesn't do itself justice on-paper Keep in mind that you may be getting a lot of good people with a lot of pros, but that don't do themselves justice on paper.

Possible, but the painful disappointments have all been the reverse. Good on paper, but the paper is, to be generous, "embellished."

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#107

Post by wlievens » Sat, Sep 17, 2011, 7:48 AM UTC

ajuc wrote: post #62

mikereedell wrote: post #34

While we don't ask FizzBuzz in particular we have a question my manager asks: If you could fold a piece of paper 50 times, how tall would it be (very rough ballpark figure)? Our success rate is surprisingly low.

What adventages this question has over asking candidate to write factorial, or FizzBuzz, or sth like that? It only checks if you can estimate the thickness of paper sheet and know powers of 2. Anybody can know that.

Perhaps if you show that you need (a) the thickness of paper and (b) the powers of too, you've shown the thinking ability to pass the question. The result value doesn't matter.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#108

Post by dhimes » Sat, Sep 17, 2011, 12:13 PM UTC

ericb wrote: post #106

dhimes wrote: post #15

Earlier quoted context omitted.

The job has a lot of pros, but probably doesn't do itself justice on-paper Keep in mind that you may be getting a lot of good people with a lot of pros, but that don't do themselves justice on paper.

Possible, but the painful disappointments have all been the reverse. Good on paper, but the paper is, to be generous, "embellished."

Sure, but it's really hard to try it the other way: "Well, he looks like a dipshit on paper, but I've just got a feeling."

I haven't hired for my own company yet, but when I did if for previous employers I found it quite hard.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#109

Post by mattdeboard » Sat, Sep 17, 2011, 12:23 PM UTC

hga wrote: post #30

mattdeboard wrote: post #7

I wish we would run at least some kind of sample problem before hiring people. sigh

Indeed; if you interview at a company that doesn't to this sort of thing if you have any choice you're well advised to avoid them. There's simply going to be little joy working with people who can't program and can either stick around or who have to get fired. And things can get ugly for those who do have a clue, from envy to having to do others work to avoid project or company failure and losing your job.

> There's simply going to be little joy working with people who can't program

Well, it does make for exciting bitch sessions in IRC.

Re: Ask HN: What % of your job interviewees pass FizzBuzz type questions?

#110

Post by rmc » Sat, Sep 17, 2011, 1:48 PM UTC

lotharbot wrote: post #85

wladh wrote: post #68

Earlier quoted context omitted.

It's not about how expensive a laptop is or isn't. If somebody can't master the basic syntax of the language so that they can write a very basic algorithm without syntax errors and in such a way that it would run on the first try, they can't be very productive. And fizzbuzz is really the rock-bottom of the simple algorithms. Even a linked-list library would be a very reasonable thing to ask (if we're talking about C…

Writing on a whiteboard while explaining yourself is different from typing alone into an IDE. Conventions you might use to avoid syntax errors (like typing a pair of braces and then filling the middle) may not work on a whiteboard. Pacing is different, and muscle memory doesn't help. You're looking at a blank whiteboard rather than your terminal with other parts of the codebase. The first few minutes of coding are of…

FizzBuzz is not aimed to find the best, the kind of people who fail fizzbuzz don't fail it for syntax errors or semicolons. People fail fizzbuzz by staring blankly at the screen/whiteboard acnd not nothing where to start, you fail fizzbuzz by not knowing how to do a loop. You fail fizzbuzz by nkt knowing how to do an if statement, you fail fizzbuzz by not knowing about modulo arithmetic. Fizzbuzz is designed to get rid of those people.