Why don't all programming job interviews involve writing a program?

Question

This discussion about Interviewing Techniques has inspired me to ask, "Why don't all programming job interviews involved writing some kind of a program?"

In my opinion, asking an interviewee to sit down in front of a computer and write a small program, in a language they claim to be proficient in, to solve a predefined problem, would weed out those candidates who can actually program, and those who can't.

I know that not all programming job interviews invlove writing a program, or even a single line of code, or even psuedo code. So my question is, why not?

Obviously one potential reason could be the time factor. I'd like to hear more about that as well as other thoughts. Thanks.

Edit: I'm not saying that I believe that writing code should be the entire interview. I think talking through a problem solving scenario and asking some computer science questions are also important parts of a comprehensive interview. I'd also make sure a candidate is proficient in revision control tool concepts.

However, I'd skip asking clichéd questions like, "What is your biggest strength, and what is your biggest weakness," maybe even, "Explain a difficult situation you faced and how you dealt with it." in order to make time for writing code.

I also think using Pair Programming during interviews is an interesting idea.

Answer 1

Programming isn't just knowing the language, it's also application of the language.

An interviewer wants to know how you think critically, solve problems, and generate a plan of action. None of those require programming. If you can't do those, there isn't a purpose in seeing how well you program, because you can't solve problems in the first place.

Answer 2

Having conducted a number of interviews personally, it's mostly an issue of time. Even a relatively simple program can take 30-45 minutes to code when the interviewee is nervous (which they often are.) When there is only 1 hour allotted for an interview, 30-45 minutes constitutes a significant portion of the interview. Sometimes interviewers feel they can get a better understanding of the candidate by asking them a number of questions instead of focusing on a single problem.

I'm not arguing against asking interviewees to write a program; I'm just saying that when they're not asked to do so, it's usually because of time. Some interviewers will ask interviewees to write some code after the interview and send it in the next day, precisely for this very reason.

Answer 3

Programming isn't just everything, it also matters your logic for solving real life problems and situations.

An analist/programmer, needs first to understand the problem to come out with a solution, how good you are at matters al lot, this is what make you different from others, it is as important as how good you are at coding in some language or how many languages you do know.

i know this sounds not like a interview scene, i agree with GMan, but might help for the general idea about good skills in a programmer.

Answer 4

I used to do a lot of interviews. It's a matter of time. I can ask someone "build me a class in pseudocode that stores a linked list", and have them doodle it on a whiteboard in five minutes.

Doing anything more complex requires more than an hour. Code a website from scratch isn't something I need you to ever do, nor is playing "find the bug in this codebase you're entirely unfamiliar with". There are better questions than asking someone to code, given a one-hour window to interview.

The question that always works for me is "what did you do at your last job that you were proud of?" If they can't answer that passionately with something that's interesting to me, it's probably not going to be a good fit. That said, I also encourage "well, what did you do at a job before that?", since everyone has a dud position once in awhile.

Rotating back, the best "please code this" type of questions? Take-home assignment. I'm fine giving a promising candidate an interesting algorithm to implement (what solution did they choose?), or even a simple hour-long project just to see if they comment their code.

Back further, because "what are your biggest three strengths/weaknesses" is so cliche, everyone should have a good answer rehearsed for it, unfortunately.

Answer 5

The simplest answer? Some people are not good at interviewing, or have no idea what it is they are actually looking for, or are just poor interviewers.

This is kind of like asking "why doesn't everyone do things the best way?" There is no single answer. Some people/companies are poor interviewers and have never actually stopped to think about what it is they want to find, how they should interview candidates, what they care about in an interview, etc.

The long answer: different people value different things and therefore have different ways to try to find what it is they value.