Why we don't hire programmers based on puzzles and tricks

My point is that having someone work a day for free would be great in any industry, but somehow only we in tech tolerate this, why is it different?

Some of the best hiring strategy I've came across is indeed "test driving". Take a challenging problem your team has, slim it down and ask candidate to do some quick prototype during a weekend. No interviews, puzzles or whiteboarding :). If you were going to fly down a candidate on-site for a day of interviews instead, it's going to take same time anyway considering logistical effort on candidate's part.

Test-driving, however, is unfortunately neither scalable nor "leak proof". As soon as one candidate gives away your test drive question, the next candidate could easily cheat away inflating their apparent awesomeness compared to other better candidates.

However it would be incorrect to write down all whiteboarding interviews as "evil". Like any other interviewing techniques, it really depends on how you do it. A good whiteboarding question that allows candidate to use CS fundamentals to solve fairly non-trivial problem that you also needed to solve for your current work is a great question. There are 3 major reason why this doesn't work as expected at some large companies:

1. Interviewers can't think of good whiteboarding question and fall back to commonly asked popular puzzles. These interviewers are also often the ones who have one "favorite" question that they would ask everyone. This is absolutely #1 problem why whiteboarding interviews devolves in to secret puzzle marathon. The best questions that interviewer could ask are actually the ones that they needed to solve themselves as part of their work recently. This keeps questions relevant and refreshed regularly. It also allows to compare candidate with themselves and follow the philosophy of hiring people smarter than you. It's however hard because interviewers themselves needs to continue doing something interesting regularly.

2. Interviewers provide feedback to each other during the loop. It's not coincidence that if 1st interviewer gives "hire", all rest tend to do same at companies where there is no clear policy of not communicating feedback before end of the interview.

3. Interviewers don't follow up candidate response by extending question, building on to next level perhaps open ended scenario, asking auxiliary details such as test cases, complexity etc.

Work is social.

What do you when a couple teammates walk up to your desk out of nowhere, abruptly interrupt your coding zone, and ask you why the build broke when you changed the FoobarService to return X instead of Y when Z? They can't release the latest features until it's fixed! What you were doing isn't important anymore, you're holding up everything!

If you want to work for a web services company: what are you going to do when your service goes down, you're oncall, and angry users, coworkers or your manager start asking you what's wrong?

Are you gonna meltdown? If so, I think you should address that first. My company, which does do whiteboard interviews, can wait to hire you until you won't freak out, and we likely will.

By the way... real work actually gets worse than this. Sometimes the co-workers involved aren't gentle about things in the heat of the moment and they're gonna say you did something stupid, that your mistake was obvious. You need to address their concerns anyway. Or during an outage, your nervous manager might start checking in every 2 minutes - you need to calm him down.

I agree wholeheartedly here. I know many developers (myself included) who would fail a FizzBuzz test or any instance where they're asked to write code on a whiteboard and yet can produce some really clean, efficient and above all well-written code. How about instead of asking people to write on a whiteboard or do Computer Science 101 tests, how about you give them a computer, a problem and ask them to solve it?

Don't forget it's not always how smart they are, it's their work ethic and whether or not they'll be a good fit for your team. Personalities that meld well with already hired employees are an essential must, no point hiring an introvert for a position when the team are extremely social people who have Friday afternoon beers.

Here is a tip: hiring a developer? Ask them to write a blog application, a task management system or a real world problem they will encounter if hired by your company not some ridiculous test that could stop you hiring a great developer. I consider myself to be pretty good, but I don't have a CS degree, I suck at mathematics and can only do simple math, yet I am able to produce exceptionally great code especially in instances where deadlines are tight and sometimes unreasonable.

Back in my early 20's I applied for a job (which I was basically invited by the manager to apply for) and was extremely nervous in the interview. I got the job and turned out to be one of the most experienced in the department. They later asked me why I was so nervous in the interview, I said I thought I just really wanted the job.

I've come to enjoy technical interviews. How often do you get to spend a whole day talking one-on-one with people in your field who you can learn something from? I enjoy giving technical presentations to groups of 1000 people or so and been not nervous at all. But I have to keep water with me because some reflex makes my mouth get really dry. So I'm fine with public speaking (the most commonly cited phobia).

On the other hand, the prospect of sitting down to pay a bunch of paper bills or do taxes makes my body want to hyperventilate. If, in a place where there are only people around I know well, and I remember an event in my past that involved a social interaction in which I acted suboptimally while at the same time someone is crinkling a plastic bag, I will startle to the point of crying out "Aah!". It's true :-)

My only point here is that people are complex critters who change with time and environment. So attempts to think of others as a box of predictable glands and cortexes (cortices?) can easily turn into a pseudoscientific projection of one's own preconceptions. (I find it very helpful when thinking about myself, however.)

Has anyone ever tried asking candidates to design their own interviews?