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I can't even begin to describe how worthless I think most coding interviews are. Here's a contrived problem, that will never come up in our work. Now solve it

I can't even begin to describe how worthless I think most coding interviews are. Here's a contrived problem, that will never come up in our work. Now solve it by writing your code by hand without a compiler or any other tools that you would use in real life. I understand that these questions are often about seeing how you think and how you solve problems. Throwing annoyances like writing code on a whiteboard into a high pressure situation doesn't help that at all.

niggler 14y ago
Writing code by hand reveals far more than you give it credit for. Someone omits a semicolon? Bam, conversation about semicolons or ASI. It's not about the fanciest solution. And anyone who does it that way is foolish. It's the purest test of Language facility, and a really good springboard for all kinds of questions. Downvoters: have you actually tried to hire someone?
- gambler 14y ago
  I didn't downvote, but I disagree and I did try to hire someone. Whiteboard questions are next to useless because they are, essentially, a guessing game. The candidates need to guess what behavior the interviewer wants them to exert. Some interviewers simply use it as an idiot filter, while others want the person to explain their reasoning, wile yet another group is stupid enough to think it's representative of real coding habits of the candidate. If the candidates guess incorrectly, they will fail the question, regardless of who they are or how good they know their trade. In short, interpretation of whiteboard questions is too damn subjective.
  - lessnonymous 14y ago
    That's bad interviewing, not bad practice. Get rid of the guessing. Make sure you explain to the candidate exactly what you're looking for. I use whiteboard coding .. and it's not to catch you out on semi colons. I even tell my candidates that they can use any language they want or even mix them together or make up their own. What I want to see on the whiteboard is a logical, working solution to a simple problem. And if your brain freezes up because it's an "interview", I'm going to push you in the right direction. Once you have an initial working solution, we're going to chat about how it works. If there are cases where it would fail. What assumptions we've made about input. Maybe we'll (both) even jump over to another whiteboard and write a new version based on our discussion. (Do your eyes light up when we've found a cool optimization??) The only language caveat I use: you can't have a call a function called doitforme() (If you or anyone you know is looking for a senior PHP job in Melbourne.AU, I'm hiring. Hit me up and I'll send you to the ad on Seek)
  - niggler 14y ago
    "others want the person to explain their reasoning," I think far more people use whiteboard questions in that context than the article's author thinks. " If the candidates guess incorrectly, they will fail the question, regardless of who they are or how good they know their trade." I don't know about your experience, but in my experience candidates actually ask questions if you properly set up the problem and present an inviting atmosphere. And in my experience the best programmers are those that aren't afraid to ask good questions.
- xyzzyz 14y ago
  Conversation about semicolons? During a job interview? I'm sorry, but this is a waste of time. Why don't you talk about, you know, algorithms? Concurrency? Databases? Testing? Or anything that is more than remotely relevant to the job?
  - niggler 14y ago
    "It's the purest test of Language facility" None of your alternatives "algorithms? Concurrency? Databases? Testing?" really test language facility. Those are important, and they have their place in the interview process, but so does language awareness.
    - lessnonymous 14y ago
      Your whiteboard doesn't have an inbuilt syntax highlighter or linter that points out when I miss a semicolon. It's such a contrived situation that to expect perfectly written code is madness.
      - niggler 14y ago
        While it makes no sense in a language like C, in languages that do have automatic semicolon insertion (like JS) the question is far more interesting
    - nollidge 14y ago
      Personally, I'm vaguely aware that JS does ASI, but rather than waste brain space trying to understand it, I just use semicolons with everything. And anyway, what better test of language facility is there than having the person code something? Or looking at code they've written? Whiteboarding is a weird, artificial environment that's not going to represent the coder's natural behavior in the wild.
      - niggler 14y ago
        Putting someone in front of a computer gives them the freedom to google (true story: I used to do a paper exam, and then I found one person was googling when I was in the bathroom and left the guy unattended for a few minutes). "Whiteboarding is a weird, artificial environment that's not going to represent the coder's natural behavior in the wild." You don't use a whiteboard when you code? I love them. The whiteboard is a nice tool for doodling and free exploration. I used to print out code and write on it, but I found that process to be much slower than the whiteboard.
- mgkimsal 14y ago
  I'll go one further. I had an interview several years ago. Talking with the owners, small shop (6 people? 8?). We get to a "let's code something on the white board" segment. Fair enough. "Write me some code that does XYZ" (I honestly don't remember what it was - something basic but not trivial). I took the marker, went to the board, put the marker to the board, then turned around and asked a couple questions. They answered, I sketched out a few lines of code, and that was that. I sat down and one of them said that I was the first person ever to ask a question before writing. Everyone else had started writing, got part way through, then asked for clarification on the ambiguous parts (or worse yet, never realized part of it was up for interpretation). Everyone handles whiteboard tests differently, but it was interesting to me to get that perspective shared with me about asking questions before writing on the board.
  - lessnonymous 14y ago
    I wonder if I interviewed you. I've only ever had one or two people ask for clarification or want more detail about inputs BEFORE they start writing code.
    - bcbrown 14y ago
      I find that surprising. The advice I've gotten from everyone when interviewing at the big tech companies in Seattle is always "make sure you clarify ambiguity before writing any code". I always assume that part of the evaluation is on my ability to resolve ambiguity, and always try to clarify anything I can, sometimes including writing out an example or two and verifying we agree what the expected output should be.
    - mgkimsal 14y ago
      to be sure it wasn't writing code - whiteboarding code/pseudocode. it was a bit of an ego stroke, i think, but given the state of their company at the time, and how they advertised the position, i don't suspect they were getting many sr-level developers applying. i applied mostly cause it was close to home.
run4yourlives 14y ago
The problem is that at least 60% of people that call themselves programmers, and seemingly have no issue getting by HR, can't code fizzbuzz, let alone whatever it is you're working on. Issue one for me as an interviewer, whenever I've needed to be in such a position, was just to figure out whether or not I was talking with a programmer. After that though I tend to agree with you. Beyond demonstrating basic competence - which I think in the future I will look to put into some for of pre-interview screening - code writing tests don't do much. Personally, I've found bringing my current work in with me and talking about different ways of solving the issue seems to work pretty well.
- Falling3 14y ago
  I've heard various numbers like this thrown around, but I'm having a hard time seeing how it could possibly be that high. Is that figure coming from personal experience? I also struggle with that idea since I'm very capable of programming fizzbuzz and a lot more, but am still having a problem finding a new position.
  - run4yourlives 14y ago
    Is that figure coming from personal experience? Actually, if I went purely on personal experience it would be closer to 90%. I tempered it because I can't believe it could be anywhere that bad. It's sad, but from what I've seen, applicants fall into two major groups, for the most part: 1. People who seem to know how to code (as in, actually use a keyboard) but who don't possess any type of critical thinking skills and can't actually figure out how a piece of code can solve a real world business problem - or even care - unless you tell them exactly how it should work. These people tend to live in big corps and stop coding completely at 4:59 everyday. 2. People with computer science degrees (the more the better) that can think up wonderful and complex solutions to the most basic of problems but can't seem to figure out a syntax error, or understand that a landing page does not require a $40K investment in the latest oracle database software, or that it doesn't matter how wonderful their design is if nobody can figure out how to use it, or that yes, it was more important to have it out last month than it was to make it run 30% faster. Both of these hires are disasters. Unfortunately, the third group, the ones that can understand what a user is saying, design a simple way to achieve the goal, and where appropriate link it to other related features in a meaningful way, are few and far between. Most of them are working in small shops and never have the need to apply for a position via interview, since they get scooped up on reputation before that.
Falling3 14y ago
Not too mention that many of those contrived problems are recycled, so a little studying goes a long way. What exactly does that prove?
- lessnonymous 14y ago
  It's not a test of your ability to recollect something. It's a conversation. If you're just regurgitating the greatest code solution ever but can't explain why it's so damned good then you're not very impressive. There ARE contrived problems that you can just regurgitate an answer for. (Why are manholes covers round? Because manholes are round duh!) And if anyone asks you one from the lists that are on the interwebs, they're probably just asking because that's What Google Does

niggler 14y ago

Writing code by hand reveals far more than you give it credit for. Someone omits a semicolon? Bam, conversation about semicolons or ASI. It's not about the fanciest solution. And anyone who does it that way is foolish. It's the purest test of Language facility, and a really good springboard for all kinds of questions. Downvoters: have you actually tried to hire someone?

gambler 14y ago
I didn't downvote, but I disagree and I did try to hire someone. Whiteboard questions are next to useless because they are, essentially, a guessing game. The candidates need to guess what behavior the interviewer wants them to exert. Some interviewers simply use it as an idiot filter, while others want the person to explain their reasoning, wile yet another group is stupid enough to think it's representative of real coding habits of the candidate. If the candidates guess incorrectly, they will fail the question, regardless of who they are or how good they know their trade. In short, interpretation of whiteboard questions is too damn subjective.
- lessnonymous 14y ago
  That's bad interviewing, not bad practice. Get rid of the guessing. Make sure you explain to the candidate exactly what you're looking for. I use whiteboard coding .. and it's not to catch you out on semi colons. I even tell my candidates that they can use any language they want or even mix them together or make up their own. What I want to see on the whiteboard is a logical, working solution to a simple problem. And if your brain freezes up because it's an "interview", I'm going to push you in the right direction. Once you have an initial working solution, we're going to chat about how it works. If there are cases where it would fail. What assumptions we've made about input. Maybe we'll (both) even jump over to another whiteboard and write a new version based on our discussion. (Do your eyes light up when we've found a cool optimization??) The only language caveat I use: you can't have a call a function called doitforme() (If you or anyone you know is looking for a senior PHP job in Melbourne.AU, I'm hiring. Hit me up and I'll send you to the ad on Seek)
- niggler 14y ago
  "others want the person to explain their reasoning," I think far more people use whiteboard questions in that context than the article's author thinks. " If the candidates guess incorrectly, they will fail the question, regardless of who they are or how good they know their trade." I don't know about your experience, but in my experience candidates actually ask questions if you properly set up the problem and present an inviting atmosphere. And in my experience the best programmers are those that aren't afraid to ask good questions.
xyzzyz 14y ago
Conversation about semicolons? During a job interview? I'm sorry, but this is a waste of time. Why don't you talk about, you know, algorithms? Concurrency? Databases? Testing? Or anything that is more than remotely relevant to the job?
- niggler 14y ago
  "It's the purest test of Language facility" None of your alternatives "algorithms? Concurrency? Databases? Testing?" really test language facility. Those are important, and they have their place in the interview process, but so does language awareness.
  - lessnonymous 14y ago
    Your whiteboard doesn't have an inbuilt syntax highlighter or linter that points out when I miss a semicolon. It's such a contrived situation that to expect perfectly written code is madness.
    - niggler 14y ago
      While it makes no sense in a language like C, in languages that do have automatic semicolon insertion (like JS) the question is far more interesting
  - nollidge 14y ago
    Personally, I'm vaguely aware that JS does ASI, but rather than waste brain space trying to understand it, I just use semicolons with everything. And anyway, what better test of language facility is there than having the person code something? Or looking at code they've written? Whiteboarding is a weird, artificial environment that's not going to represent the coder's natural behavior in the wild.
    - niggler 14y ago
      Putting someone in front of a computer gives them the freedom to google (true story: I used to do a paper exam, and then I found one person was googling when I was in the bathroom and left the guy unattended for a few minutes). "Whiteboarding is a weird, artificial environment that's not going to represent the coder's natural behavior in the wild." You don't use a whiteboard when you code? I love them. The whiteboard is a nice tool for doodling and free exploration. I used to print out code and write on it, but I found that process to be much slower than the whiteboard.
mgkimsal 14y ago
I'll go one further. I had an interview several years ago. Talking with the owners, small shop (6 people? 8?). We get to a "let's code something on the white board" segment. Fair enough. "Write me some code that does XYZ" (I honestly don't remember what it was - something basic but not trivial). I took the marker, went to the board, put the marker to the board, then turned around and asked a couple questions. They answered, I sketched out a few lines of code, and that was that. I sat down and one of them said that I was the first person ever to ask a question before writing. Everyone else had started writing, got part way through, then asked for clarification on the ambiguous parts (or worse yet, never realized part of it was up for interpretation). Everyone handles whiteboard tests differently, but it was interesting to me to get that perspective shared with me about asking questions before writing on the board.
- lessnonymous 14y ago
  I wonder if I interviewed you. I've only ever had one or two people ask for clarification or want more detail about inputs BEFORE they start writing code.
  - bcbrown 14y ago
    I find that surprising. The advice I've gotten from everyone when interviewing at the big tech companies in Seattle is always "make sure you clarify ambiguity before writing any code". I always assume that part of the evaluation is on my ability to resolve ambiguity, and always try to clarify anything I can, sometimes including writing out an example or two and verifying we agree what the expected output should be.
  - mgkimsal 14y ago
    to be sure it wasn't writing code - whiteboarding code/pseudocode. it was a bit of an ego stroke, i think, but given the state of their company at the time, and how they advertised the position, i don't suspect they were getting many sr-level developers applying. i applied mostly cause it was close to home.

run4yourlives 14y ago

The problem is that at least 60% of people that call themselves programmers, and seemingly have no issue getting by HR, can't code fizzbuzz, let alone whatever it is you're working on. Issue one for me as an interviewer, whenever I've needed to be in such a position, was just to figure out whether or not I was talking with a programmer. After that though I tend to agree with you. Beyond demonstrating basic competence - which I think in the future I will look to put into some for of pre-interview screening - code writing tests don't do much. Personally, I've found bringing my current work in with me and talking about different ways of solving the issue seems to work pretty well.

Falling3 14y ago
I've heard various numbers like this thrown around, but I'm having a hard time seeing how it could possibly be that high. Is that figure coming from personal experience? I also struggle with that idea since I'm very capable of programming fizzbuzz and a lot more, but am still having a problem finding a new position.
- run4yourlives 14y ago
  Is that figure coming from personal experience? Actually, if I went purely on personal experience it would be closer to 90%. I tempered it because I can't believe it could be anywhere that bad. It's sad, but from what I've seen, applicants fall into two major groups, for the most part: 1. People who seem to know how to code (as in, actually use a keyboard) but who don't possess any type of critical thinking skills and can't actually figure out how a piece of code can solve a real world business problem - or even care - unless you tell them exactly how it should work. These people tend to live in big corps and stop coding completely at 4:59 everyday. 2. People with computer science degrees (the more the better) that can think up wonderful and complex solutions to the most basic of problems but can't seem to figure out a syntax error, or understand that a landing page does not require a $40K investment in the latest oracle database software, or that it doesn't matter how wonderful their design is if nobody can figure out how to use it, or that yes, it was more important to have it out last month than it was to make it run 30% faster. Both of these hires are disasters. Unfortunately, the third group, the ones that can understand what a user is saying, design a simple way to achieve the goal, and where appropriate link it to other related features in a meaningful way, are few and far between. Most of them are working in small shops and never have the need to apply for a position via interview, since they get scooped up on reputation before that.

Falling3 14y ago

Not too mention that many of those contrived problems are recycled, so a little studying goes a long way. What exactly does that prove?

lessnonymous 14y ago
It's not a test of your ability to recollect something. It's a conversation. If you're just regurgitating the greatest code solution ever but can't explain why it's so damned good then you're not very impressive. There ARE contrived problems that you can just regurgitate an answer for. (Why are manholes covers round? Because manholes are round duh!) And if anyone asks you one from the lists that are on the interwebs, they're probably just asking because that's What Google Does