Hello, my name is David. I would fail to write bubble sort on a whiteboard. I look code up on the internet all the time. I don't do riddles.— DHH (@dhh) February 21, 2017
I'm not a huge fan of the whiteboard interview but I think many of the tweets missed the point. Most of the whiteboard interviews I'm aware of involve algorithmic problem solving while the tweets, at least the ones I've seen all refer to things that indeed one would look up. Things like API calls - not things that whiteboard interviewers typically care about.
Tim Bray takes that point of view and shared his thoughts in a recent blog post.
The idea behind the whiteboard interview isn't all bad. The interviewer has an opportunity to see how the candidate thinks and works through a problem and in an ideal situation the interviewer is, at least to a point, coaching the candidate to help them through the process. It seems to me that the problem lies more in the types of questions asked and the skill of the interviewer rather than the idea that candidates work through a problem live.
I'd imagine that whiteboard interview success skew towards candidates who work well in isolation in a short period of time, have a good amount of exposure to these types of algorithmic problems. Also those who have practiced and trained specifically for the interview will have a huge edge. For people new to the process, it can be very stressful.
Once a candidate has accepted a position, they'll likely be working with a team, with additional resources, and with time to solve problems. This is a very different environment. The whiteboard interview, much like the SAT is thus something of an arbitrary gatekeeper that a candidate must prepare for and conquer rather than a skill that they must develop that will make them a more productive team member.
This whole process tends to advantage those with the time and background to prepare - this is one of the places where the argument that whiteboard interview hurt diversity come from.
I could be totally wrong but I seem to recall that the whiteboard interview, at least in terms of external visibility grew out of the legendary Google puzzle interview questions.
A tech giant like Google can interview however they like and they'll still get the talent. They go to the most selective institutions where candidates have already been culled for success. If they then interview 100 candidates and 10 of them would be good fits, as long as a couple thrive through the whiteboard interview process, they'll get their engineer. They'll miss out on a lot of great talent but they can cast such a large net they'll fill there seats with productive employees.
On the other hand, smaller companies will certainly miss out on great talent if they follow the same approach.
Is there a better way?
Some companies pre-assign mini projects and then discuss that at the interview. Pairing could also be a lower stress alternative to the technical interview. Another option would be to look at a candidates existing projects.
An interesting question is "why do so many companies use the whiteboard interview?" I can't say for certain but I wouldn't be surprised if it was a simple as "because Google does it."
For over 100 years, Stuyvesant high school required students study mechanical drawing (drafting). The relevance of the subject lessened over the decades and what was taught in many ways has become a joke. A typical class during the CAD parts of the class might be going over the cylinder command in CadKey. That's like spending a day studying the edit menu in Microsoft Word in an English class. If you can't tell, I'm not a fan. Drafting at Stuyvesant is the vestigial organ of the course of study.
My point isn't to bash drafting at Stuy but rather that there have been any number of schools that require their students take drafting even though it doesn't prepare students for, nor lead them to anything else in the schools curriculum (which now can be said for Stuy's drafting requirement). I've spoken to teachers and principals at these schools and we go back and forth as I press them for the reason for the requirement and ultimately, they tell me that their school requires drafting "because Stuyvesant does."
Why do so many small companies employ the whiteboard interview? Because the big kids do. The trouble is that the big kids can get away with it, the smaller players on the other hand, are hurting themselves. Even the bigger players would be well served to try to come up with an interview process that better assesses fit rather than a course filter that while it does pull in talent misses talent as well.