What would be a good 4-hour development task for a job interview?

I don't really like that kind of tests for a couple of reasons 1) They're not applicable to how development really works In four hours they can only be expected to make something rudimentary. What does that really tell you about their skills? 2) Working from "nothing" is really hard for such a short period of time Sure it's a skill but is it something you should judge everyone from? You'll filter out anyone that's a bit more deliberate that might be very fast once they get going A better test IMO would be to have an existing solution, done in the technologies you find most relevant. There should be a description with "goals" for the solution, like "support multiple languages", "be testable", "Performance"-criterias etc. The solution would also have a number "flaws" relation to those goals and dependencies/architecture in general. Their job would be to refactor the solution as appropriate and also describe potential flaws that can't be fixed within the time-frame and how they could be resolved. This should test their skill on a more real-life project as well as code comprehension, refactoring, performance and architecture skills Sidenotes If you're by doing this kind of interview are saying that they need to be able to perform under tight deadlines and a stressful environment you're also telling your candidate that your job kinda sucks, to which degree is arguable of course. Overall I'd also like to add that I think "testing" is a lot less accurate at predicting a programmer's skill than judging him on his prior work, his references and his passion for the craft. It's good for weeding out the obvious unqualified but not much more than that. It's worth nothing that good candidates are evaluating you as much as you're evaluating them. They're have options and if you're lucky enough to find one looking for a job you should "sell" your company as much as they have to "sell themselves". A perfect employeer-employee relationships is like the perfect relationship: two parties which lots of options that choose each other :)

I have hired quite a few developers over the years, and I am more and more moving away from these technical skills tests. I usually have a basic questionnaire with a mix of multiple options questions and free form questions to establish some basics on technical skills. However, I have found that most people can pick up technical skills. That's not where the problem lies. What is really important is to figure out how this candidate will fit in with the rest of the crew. How does he communicate? How does he operate within a team? Will (s)he follow existing policies or will (s)he insist on doing things his/her way? I have had contractors who absolutely excelled at the technical level, but were a complete nightmare when it came to managing them. OTOH, I have had junior developers who were not all that great at coding, but formed a great team and performed well after a short period of time.

How would a Failure Look? With basically only one datatype (Currency Exchange Rate) there's not much to repeat (DRY), and i would argue, that using more than what the framework provides out of the box would be a case of 'Yagniy' (so, little database design and MVC), and your requirement so far does not impliy any Javascript (a HTML-Table is also a presentation, and even a nice flash graph can be implemented by providing only a dataview and using one of the free flash graphs to do the rest). While the test really lowers the chance, that a non-fiz-baz-compliant candidate slips through, it seems to me, that it doesnt proove much more, and a candidate, who manages to demonstrate the virtues you search for in a quantity that can be measured, would tend to overengineer. Better ways to fail I would suggest, that you implement the application yourself, present it with the specs to the candidate, and ask him to implement a change request. This way, there is a chance for failure (DRY is violated, if he implements already existing features once more, MVC is violated if he just fumbles a little in the view instead of propagating the change to the business objects, etc) Also, the Bias against Frameworks with facilities for setting up new projects would be eleminated. There would be a new Bias against the chosen Technology, but if you choose the same technology he would be working with that should not be an Issue.

The thing is, if you do something like this, then the interviewee thinks this is how he will be treated normally. Your company is under scrutiny from their side too. I.e. Putting an interviewee under extreme pressure to perform with high risk of failure means less happy interview outcomes and less chance of getting a good candidate. But, it can be done in a way as to cover knowledge although not as a core interview technique. e.g. I have done a pair programming session with an experienced programmer at the company I was being interviewed at. This worked well as the tasks we performing were simple, and covered various subjects within programming scope.

I tried to think of a good "full web dev stack" task once, and the best I could come up with was something involving autocomplete. Autocomplete could involve JavaScript, UI work, Ajax, backend work, hitting a database/data store… It's a pretty small and limited task that touches the full stack. That said, I haven't actually tried assigning someone this task during an interview, with or without time limit, so I can't speak to how well it works in practice.

4 hours is I think too long and time waster for the developer. To be fair, do something quick may be half an hour. I dont like injustice with developers. If you let him sit for 4 hours and he can do his job, better pay him for his time if you not hire him. Please respect our developers. They are one of the difficult and one of the least appreciated ppl on this planet. I agree with other answers. One of the basic things is how well do you get along with the developer. Somekind of test is always welcomed by the developer just so he/she can prove his skills. I was asked a half an hour test just likes yours but shorter. I was asked to implement something like "A user login int and submits a review, All of it is stored in the database". If I could not write the code then pseduo code was acceptable. I had internet access and he could actually see my screen what I am doing. This was a trivial task for me. He came in after 15 min (I believe) and looked at my code. I did do thing the perfect way which gave him an idea (I made out points which previous develper disn't make), I know things pretty well. But then he reject me because he said you did not indent the code proper. I said, well this is just a test to get thing done but anyways. What was wrong? He did not like my personality. And I think that is the no 1 reason I can not land a job. I dont have a charming personality and that means I may be unfit for most jobs. Not to mention that I extremly kind, polite, love rules and a very good listener. He talked about me perhaps not well dressed, etc. So I think a test is a great idea, but 4 hours is a bit too long. I have had test before which was I completed at home, they worked but I did not get hired :) So the thing is consider a developer for basic skills, dont abuse him. If he knows the stuff and is acceptable to work with, you can hire him. Thanks

"Is it even possible to figure out a good problem set for such a short time that truly test all the above abilities of candidates?" It is possible. But, it goes too far when you propose a 4-hr coding task for a candidate who has just walked into your office. Some people take time to adjust to new environments. When someone comes to you for an interview, s/he is obviously coming for a discussion not for an actual project. That's the mindset we carry when we go to some new place of work. Putting a candidate through a 4-hr exercise immediately might build up unnecessary stress. I think it's a bad idea in general to carry out such large coding exercises during interviews. It's like when you are auditioning for an actor, asking him to do a short film on the spot. A good idea would be to ask the candidate if some of his past work/code/design can be reviewed during the interview. It is never possible to "truly" test all the abilities required for a programming job. A good way is to have a problem set and have an open discussion about specific choices, important design decisions, data structures over the problem set. If you insist on some coding exercise, you can give them a problem set prior to the interview and ask the candidate to submit a solution before they turn up for the interview.

We do these but as a 2nd round interview, with plenty of warning to give the candidates a realistic chance. Task is typically a rather real-world one in my organization -- build a 3 part registration form. It has the right amount of depth and breadth and is really applicable.

I'd give them a snapshot of a previous project to work from and have them improve some part of it (optimize a bottleneck, fix a bug, introduce a pattern,...) this is what they'll be doing 99% of the time they are working with you things to pay attention to are: readability/maintainability of the resulting "fix" if it actually works how well it integrates with the existing code what else they worked on in that snapshot (what issues they saw as to be worked on) how long until they got the idea and concepts of the framework in the following interview you can then in particular ask about stuff that came up later in that project and see how they would deal with that