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I realise this is a fairly odd question to ask but in recent rounds of hiring we have noticed a rather odd trend in new developers that spectacularly fall short of our expectations. So much so that they to all intents and purposes appear to be an entirely different person to the one interviewed and tested.

We pre-screen applicants during their initial interview with a fairly nasty PHP/MySQL written test which tests both their knowledge of the PHP/MySQL as well as some fundamental aspects of application design. You cannot score highly on this test by simply memorizing the PHP and MySQL manuals (We've made that mistake in the past). I'm sure It is by no means fool-proof, but is intended to be sufficient to weed out those who have clearly lied on their resumés.

Applicants that pass this stage are offered a second interview which is followed by a 2 hour practical test where they are required to develop a small application to a given specification. They are not necessarily expected to complete the task but are judged on their approach to the given task.

Three times now he have hired the "best" applicant based on interview and test results, and each time the person that has showed up for work on the first Monday morning has been completely devoid of the skills and experience they have previously demonstrated. Each of these applicants scored over 90% on the written test and exceeded our expectations when given a practical task to complete.

Hence my coining of the phrase "Developer Twin Syndrome"

Has anyone else experienced a similar trend in hiring developers?


migration rejected from Jun 22 '15 at 3:08

This question came from our site for professional and enthusiast programmers. Votes, comments, and answers are locked due to the question being closed here, but it may be eligible for editing and reopening on the site where it originated.

closed as primarily opinion-based by enderland, durron597, MichaelT, GlenH7, Snowman Jun 22 '15 at 3:08

Many good questions generate some degree of opinion based on expert experience, but answers to this question will tend to be almost entirely based on opinions, rather than facts, references, or specific expertise.If this question can be reworded to fit the rules in the help center, please edit the question.

I know this is off topic but: Are you finding that candidates are willing to subject themselves to this kind of testing? I would never agree to a 2 hour test. What is the candidates reaction when told you need to take another 2 hour test after passing the initial test? – Morons Dec 13 '11 at 14:23
Are these tests proctored? Have you tried an internet search on key parts of the test to see if Google is being too helpful for the candidates? Some candidates will go too far to get a job for which they really aren't qualified. – Jamie F Dec 13 '11 at 15:12
The practical test sounds an awful lot like work to me, and I dislike doing work during an interview that I'd normally bill for. Moreover, this is against some employment agreements. You may be chasing off the best candidates. – David Thornley Dec 13 '11 at 15:28
Hmm 2 hours test after and initial test would be a no go for me, if you won't trust me I would not work for you, but maybe it different here in Holland (or even europe?) then in other countries – Ivo Dec 13 '11 at 15:43
What exactly happened on Monday morning to make you think they're like a "different person"? It is most likely that they do know the stuff you're testing for (I don't buy the "leaked test" theory). Perhaps they're just coming to terms with your codebase and it makes them look like don't know what they're doing? Did these three devs eventually work out? – Angelo Dec 13 '11 at 17:33

I've seen smart, smart people get dropped into a new situation and suddenly forget how to tie their shoes. Their first Monday morning is no time to be assessing their credentials.

They're madly trying to figure out how to check their new email account and get to the code repository and understand Jimmy-in-the-next-cubicle's code. Doesn't seem like a real fair time to judge them, especially after putting them through such a wringer in their interview process.

And then there's this: when you hire someone, you're committing to them just as much as they're committing to you. You're saying: Look! Here's this person. I found them and they found me, and I'm going to support them with whatever they need to be the developer I need them to be. If that's NOT the attitude you have with new hires, let me know your company name so I can avoid even bothering with your interview gauntlet.


I think you need to take a long hard look at your hiring methods and revise them heavily, you have some major problems if your "best" has been a dud 3 times. You should test your interviewers and see if they are improperly ranking interviewees. You also need to check your tests to make sure they haven't leaked, are up to date and truly do test what you think they test, it would be worth it to involve your current developers in this process, get a senior devs comments/suggestions and have a couple junior devs that have been there a while take the test. Also you need to decide if your tests are even worth it, if you are getting unqualified candidates passing the test you are wasting a ton of time. Also I'm willing to bet that your company has a bad reputation with your local pool of developers and more qualified candidates aren't applying. good programming jobs are plentiful enough that good developers can be picky which means employers can't be dicks about hiring, or offer lower pay/less benefits and expect to attract desirable candidates. Personally I would feel insulted to be asked to take a written exam and then come back another day and take a second test, I would really recommend combining these into a single day and keeping the total test time at ~2 hours so with an initial interview that's still 3-4 hours per candidate for a first interview which is a pretty long time for what seems to be an entry level position.


A common problem. I've seen a strong correlation between those that do really well on very specialiazed questions/tasks and a lack of productivity. While those that tend to answer in generalities (often to the point of seeming like they don't know much about it) tend to do quite well in the real world. Perhaps the specialist group only know those exact items and the generalist answerers can't answer specifically as they know too much in general. No matter how well we try to simulate the work conditions for applicant testing, it just doesn't happen. I don't believe there is a way to build a suitably scientific method at this time. Subjective interviews/measures still seem to hold the upper hand on getting the best employees, despite all the attempts to objectify the process.


It's likely that your tests have leaked or they don't test the knowledge of the programmer. You can teach people how to use a calculator, doesn't mean that they can do math.

You might find this a usefull read:

The problem I've always had with that is that the typical developer is an absolutely horrible interviewer. You can script them, but then they lose all usefulness as they just follow the script... :-) That's why most places have HR/Management do the interviewing despite not knowing the tech bits. At least they can do an interview without completely botching it. – Brian Knoblauch Dec 13 '11 at 17:13

Does your work environment have anything like the level of structure you have for your hiring process? It could be that you're not testing for the skills that employees will need in order to find a useful role in the company.

If your company's culture gives employees a good deal of autonomy, you might want to try to test more for candidates with the soft skills to deal with that rather than testing on pure technical merit.