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Today's Coding Interview Game

shubharamani.com

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Re: Today's Coding Interview Game

#81

Post by agentultra »

Coding problems in interviews can be a put off for me (though not a complete turn off if everything else about the job looks good).

1. It shows unfamiliarity with my work. It seems rude to invite me all the way into your office just to be filtered. In a perfect world (or at least the one I knew some years ago) I'd be invited into an interview because you were already familiar with my work and wanted to talk to me -- not just to see if I was worth talking to in the first place.

2. Anxiety. I don't operate normally under conditions where everything I say is being evaluated.

3. They can be easily regurgitated.

4. They don't really tell you anything unless you know what you're asking for. I've been in interviews for web development positions where we started getting into the finer details of C++, sorting algorithms, and file system implementations. These are positions where I was being asked to write web applications in Python. I've been writing web applications in Python for years -- I don't think I've ever actually needed to implement a file system or even write a sort routine (tim sort is pretty good and most sorting in web apps is done by search engines or rdbms's anyway).

The problem is most people seem to think that since Google does it, they should do it too. However, if you don't know how to ask the right questions, you're just going to waste everyone's time. My time has been wasted in interviews as the interviewee. Boring technical questions that lead no-where and have little to do with the relevant skills for the job; often just for the sake of asking technical questions and appearing smart. Anyone can do that even if you yourself don't know the answers.

In a perfect world you wouldn't need to look at my resume to remember my name when I walk in the door. You wouldn't need to bother "screening" me. You want me to be there to meet me and see if I'm the right fit for the job.

But I also understand that businesses get a mountain of resumes and that some large portion of them just aren't worth looking at. It'd be nice if there was some way that you could at least know where to look in the pile for relevant resumes. That way you could spend less time screening (how draconian sounding) and more time interviewing. Sounds like a problem some decent software could solve...

Re: Today's Coding Interview Game

#82

Post by bmj »

edw519 wrote: post #80

on a white board, no syntax errors, compilable Huh? You're worrying about whether or not what you write on a white board will compile? How do you know? Press a magic button to OCR what you've written, download it into some computer somewhere, and compile it? Sounds like you're interviewing at firms with technology I didn't know existed. Your interviewers have you code on a white board so that they can evaluate you ,…

I agree, though I think, perhaps, the author has a point about something. It's one thing to be asked to write code on the whiteboard for a practical problem. During the interview process for my current employer, I was asked to sketch out a database design for a given application, including actually writing out some of the SQL to generate the tables, constraints, etc. I was then asked to write queries to pull reports against my schema. I was also asked to show some code to pull said queries from the database, in the language of my choice.

Those sorts of questions seems appropriate for the position in question. Asking me to implement a linked list or binary tree? Not so applicable. Might I use these sorts of things? Yeah, but the senior engineers assume I know how to use Google.

Re: Today's Coding Interview Game

#83

Post by grayhairmomma »

mikeklaas wrote: post #8

If I found this article by a potential applicant, I'd be much less likely to hire them. Besides the obvious red flag of the sentiment why should I have to code at a programming interview , the knowledge that they have been rejected by many other companies would make me worry.

Sorry you feel that way. Several hiring managers from top companies feel differently than you though, because they have contacted me directly and even asked me to apply at their companies. Does this mean that I've got an instant job ? Of course not. I still have much proving to accomplish -- to these hiring managers and their crew. But they obviously see a glimpse of something special in me -- which you don't.

I speak my mind...I live authentically. Yes, it's a risk to live that way, but I am willing to accept the consequences of my actions.

Re: Today's Coding Interview Game

#84

Post by grayhairmomma »

edw519 wrote: post #80

on a white board, no syntax errors, compilable Huh? You're worrying about whether or not what you write on a white board will compile? How do you know? Press a magic button to OCR what you've written, download it into some computer somewhere, and compile it? Sounds like you're interviewing at firms with technology I didn't know existed. Your interviewers have you code on a white board so that they can evaluate you ,…

Thanks for your support. The reason I mention "on a white board, no syntax errors, compilable" is because I've been dinged at the whiteboard for these silly reasons. No shit ! And Gayle Laakmann, author of "Cracking the Coding Interview" actually says it's important to write nearly perfect code at the whiteboard.

Re: Today's Coding Interview Game

#85

Post by metageek »

darwinGod wrote: post #68
RiderOfGiraffes wrote: post #64

Earlier quoted context omitted.

I hired someone who did brilliantly on walking and talking through all the conceptual issues. Turned out they couldn't code, and they couldn't touch someone else's code without breaking it. I need to see someone code.

Like the subtle use of the word 'they', incorrect grammatically,correct politically

Using "they" for an ambiguous singular pronoun is perfectly good English. It was deprecated by Victorian grammarians who wanted English to be like Latin (the same people who ordered us not to boldly split infinitives).

Re: Today's Coding Interview Game

#86

Post by chollida1 »

tgflynn wrote: post #4
jchonphoenix wrote: post #2

I understand where the author is coming from because many interviews questions are unreasonable and test absolutely nothing. However, if someone couldn't code a linked list on a whiteboard, I'd be severely worried. Same goes for a binary tree. If you know what a linked list or binary tree is, you should have no issues figuring out how to represent them with code in 10 minutes. The other trickier problems are there to…

They'd rather reject 95% of the qualified people and 99.9% of the unqualified people rather than 94% qualified and 99.5% unqualified. And then they complain that they can't hire developers. I don't think these types of interviews are well conceived. Human memory is extremely context dependent and a whiteboard/interview type situation doesn't establish the right context for someone who's accustomed to working alone wi…

> Also the more knowledge you have the more difficult it becomes to retrieve that knowledge quickly.

I've never heard this about the human brain before.

I'm not saying you're wrong, because I don't know, but statements of fact like this deserve a good reference.

Do you have anything to back up this assertion of fact?

Re: Today's Coding Interview Game

#87

Post by pitdesi »

I'd be interested to know what people think about coding pre-screening tests in general. As is obvious from my profile, I'm working on a startup trying that helps companies and recruiters easily implement coding tests to weed out people who can't code. This is a bit different than asking someone to whiteboard a solution - we're aiming to help companies get from a few hundred resumes to the top 10 or 15. We've commonly heard the problem (and experienced it first-hand) that people can't code, and we think coding tests helps solve that problem. I think it's a better solution than going by your past experience, because that's often fluff.

Re: Today's Coding Interview Game

#89

Post by Symmetry »

darwinGod wrote: post #68
RiderOfGiraffes wrote: post #64

Earlier quoted context omitted.

I hired someone who did brilliantly on walking and talking through all the conceptual issues. Turned out they couldn't code, and they couldn't touch someone else's code without breaking it. I need to see someone code.

Like the subtle use of the word 'they', incorrect grammatically,correct politically

What do you mean grammatically incorrect? The singular they was used by Shakespeare for heaven's sake, its not some recent invention. Rather, the prejudice against the singular they (and the split infinitive) stem from when people looked down on ways in which English deviated from the rules of Latin. Personally, I think its silly to call any construct thats been in use for hundreds of years among educated people% and serves a useful purpose "ungrammatical".

%The Chicago Manual of style lists "Addison, Austen, Chesterfield, Fielding, Ruskin, Scott, and Shakespeare."

Re: Today's Coding Interview Game

#90

Post by aplusbi »

bmj wrote: post #82
edw519 wrote: post #80

on a white board, no syntax errors, compilable Huh? You're worrying about whether or not what you write on a white board will compile? How do you know? Press a magic button to OCR what you've written, download it into some computer somewhere, and compile it? Sounds like you're interviewing at firms with technology I didn't know existed. Your interviewers have you code on a white board so that they can evaluate you ,…

I agree, though I think, perhaps, the author has a point about something. It's one thing to be asked to write code on the whiteboard for a practical problem. During the interview process for my current employer, I was asked to sketch out a database design for a given application, including actually writing out some of the SQL to generate the tables, constraints, etc. I was then asked to write queries to pull reports…

It's often hard to ask relevant questions that will fit into the time allotted for an interview. Your DB schema example is a good one - it shows that the candidate can design (and to a lesser extent, implement) an application. Your example (I'm assuming) is missing strong algorithmic problem solving however. It would be good to have an additional question to test this kind of knowledge.

It's also important to realize that most technical interviews are really about weeding out bad candidates than finding good ones.

It may also be necessary to have questions general enough that any given candidate stands a chance at solving it. If a candidate doesn't have SQL experience your example would be bad (assuming the company didn't require SQL experience).

This is why you see questions like "implement a binary tree." Any competent programmer should be able to implement a binary tree. If they have never seen a binary tree before, they are simple enough to describe in 5 minutes.

I once asked a candidate to implement a trie. He had never heard of a trie before so I drew one on the whiteboard and briefly explained it. He asked me a few questions and then proceeded to implement one. We then discussed the pros and cons of different methods to store the nodes (vector, list, map). It showed me that, given a spec, he could code a data structure and the following discussion showed me he understood memory and time constraints.

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