Why we don't hire programmers based on puzzles and tricks

Post by jameshart » Sat, Feb 23, 2013, 9:10 PM UTC

suresk wrote: post #435

jameshart wrote: post #429

Earlier quoted context omitted.

And at 1), you went wrong, in any language where strings are in unicode. Combining characters, byte order markers, surrogate pairs... And this is why I dislike the 'reversing a string' question. Because if you actually know anything about real world string handling, you know that correctly reversing a string is impossible, because there just isn't any logical way to reverse some constructs. How do you reverse a strin…

That is a really good point and it complicates a lot of string-based questions, which is why they are almost always constrained (either implicitly or explicitly) by assuming that the string is ASCII only, which seems reasonable to me. There are probably better filter questions to use that don't require as many artificial constraints.

Post by mark-r » Sat, Feb 23, 2013, 10:14 PM UTC

rdtsc wrote: post #407

mark-r wrote: post #399

Earlier quoted context omitted.

And you would have gotten an instant fail on the "cultural fit" criteria.

Good!

Post by mamcx » Sat, Feb 23, 2013, 11:34 PM UTC

rdouble wrote: post #436

suresk wrote: post #403

Earlier quoted context omitted.

I don't see how reversing a string is a "puzzle" - I'd put its difficulty on par (or maybe slightly harder than) fizzbuzz. In most mainstream languages, it requires 2 pieces of knowledge: 1) That a string is implemented as an array of characters. 2) How to reverse an array. The implementation is straightforward and should be trivial for just about anyone who's done much development. I don't know that the question is…

Reversing a string was initially a good interview question because in C you can keep probing multiple levels of knowledge with it. You learn if the interviewee knows the algorithm, then if they understand how to do it in place with a pointer, then if they understand the XOR pointer trick. It's not a very interesting problem in a language like Ruby or Python.

Post by kragen » Sun, Feb 24, 2013, 5:02 AM UTC

freework wrote: post #275

kragen wrote: post #250

Earlier quoted context omitted.

You mean ' '.join(the_string.split()[::-1]). Which is a totally reasonable thing to do, but doesn't exercise the same kind of thinking as doing it letter by letter. Can you solve it letter by letter, even now that you're not in an interview?

Doesn't exercise the same kind of thinking as doing it letter by letter? So what? Solving this problem in haskell doesn't show the same kind of thinking as solving it in PHP, whats your point? You basically saying you have to solve this problem they way I say you have to. Thats a sure-fire way to tell if the company is worth working for or not.

Post by touristtam » Sun, Feb 24, 2013, 1:44 PM UTC

hexagonc wrote: post #50

RyanZAG wrote: post #3

I think in addition to the measures he says, if you're hiring for a web position, it's good to make sure they understand how the stuff they're using functions. If they don't have a good grasp of how http works / url parameters / that kind of thing, then they can have some nice looking code which seems to work, but has faulty assumptions that can be security and bug nightmares down the road. Of course, you could alway…

Of course, you could always take smart people and train them - but seriously, who does that anymore? The sad truth about this is that I think many companies are afraid an employee will leave shortly after receiving training. They fear that a competitor will entice away the employee without incurring the training cost. Of course, one way to avoid this is to make the work environment desirable enough so that no one wan…