Test-based interviews: my own weird experiences

Earlier today I read two posts that examine technical interviewing:

• Technical testing during an interview: why it does not work
• The Technical Interview: An Update

These were written by my friend Mike, who’s a network security expert, is highly technical, and has a remarkable mind for detail and inquiry. I guess that’s my way of saying that his opinion on the matter is probably worth listening to.

Those posts got me thinking about my own interview experiences. Yes, many years ago I was considered “technical”, and I worked in engineering roles in development and quality assurance at companies ranging from doomed start-ups to industry behemoths to national space agencies.

In my experience, most of the interviews for programming (I use it generically) roles were a fairly even split between a technical evaluation and personality assessment. For the most part, the technical component consisted of a discussion to establish the reliability of résumé claims, ability to think abstractly, and determine level of depth with particular technologies. It wasn’t uncommon for the interviewer to ask me to write pseudocode to solve some problem, answer questions about appropriate and optimal algorithms, and tackle technical brain-teasers the like of which Google has made famous (but which have existed forever).

Note that in the previous paragraph I said “most”. Two interviews stand out in my mind as being considerable exceptions, and I share those experiences with you today.

Interview #1: Twenty Questions. That is all.

This interview was for a development position at Arius Software in Waterloo. It’s not uncommon in the co-op program for a company to start things off by hosting a group presentation to all the candidates selected for interviews: this is simply an efficient means of communicating general information, and saves the interviewer from repeating the same introductory information to every candidate individually. In Arius’ case, the group session was a bit different: it consisted of the founder/CEO saying essentially, and as directly as I’m paraphrasing, “The interview will consist of twenty questions. The moment I determine that you aren’t right for the job, I’ll end the interview. I don’t want to waste my time or yours.”

“Well,” I thought to myself, “that’s gonna be neat.” (no, really, I enjoy interesting challenges)

While I lasted through all twenty questions (yay, personal victory!), I regret that I only remember one of them: “How would I deliberately cause a memory leak in Java?” (Java has a built-in garbage collector, so memory leaks aren’t really supposed to happen) Now, I’d used Java quite a bit, but I had to admit that I had no idea how to cause a memory leak. During the interview, though, I was curious as to why I would want to achieve such a thing. So I stopped the founder/CEO and politely asked. If I remember correctly, he said that it was a useful test case.

Later, after some unknown number of exceptionally obscure and, in my opinion, trivial questions (they primarily tested your familiarity with corner cases rather than your ability to think and problem-solve) I interrupted and asked where the heck all these questions came from. He replied that every single one was a real scenario that Arius’ engineers had encountered. I think I was the only candidate who would’ve interviewed to ask questions, but hey – when you’re batting about 4 for 13 on answers (and there’s, literally, a sheet with 20 squares that are receiving a checkmark or an X right in front of you, so you know how you’re doing) you don’t have much to lose and can succumb to curiosity.

I remember distinctly knowing strongly that I did not want to work there (so you’ve hired people entirely based on trivial obscurities? I’m sure that work environment is just terrific).

Not that I had the option of turning them down, as in a complete non-surprise I did not receive a job offer.

Interview #2: The three-hour generalized aptitude test

I remember little about this company other than:

• They were based outside Pittsburgh
• The guys drove up to Waterloo to conduct the interviews
• My prospective boss was a former professional soccer player

Like Arius, these guys had a group session to describe the company and interview process. As it happened, the “process” was a three-hour generalized aptitude test consisting of about ten subsections that were individually timed. Apparently the CEO was a believer in some named school of thought that the best predictor of on-the-job performance was this massive test. The job offer would go out to the person with the top score. If he or she declined, then they’d call up the next person, and on down the line.

Now, I’ve always loved these types of tests (and math contests, and so on)…I felt they separated the abstract and applied thinkers from the rote memorizers. I figured I’d do pretty well. Plus, at that stage my technical skills were surpassed by most of my peers, as I came into UW with relatively little computer experience, so I was happy for any edge I’d get.

So what was on this test? I remember few details, but here’s the gist:

• Each section was timed, so you’d be told, “Section one is twenty minutes, begin.” And it was old-school pencil in a multiple choice answer key.
• There was a section on pattern recognition, so you’d get a long stream of alphanumeric characters and you’d have to complete the sequence. Some of these were easy, but some were impressively deep…like the pattern doesn’t appear until you’re 80 characters in. Mad stuff, and fun as hell. The trick is to zombie out and see the forest, not the trees.
• There was a section on quick computation. You had 20 minutes to answer 100 multiple-choice questions like: “select the closest answer: 6032 x 394”. Goodness profanity, you think, I’ve only got 12 seconds to answer that?? Ah, but here’s the trick…the question can be roughly approximated as “6000 x 400”, which is “24 and five zeroes”. When you look at the multiple choice answers, only one of them (2,376,608) is in the neighbourhood of 2,400,000. Now just do that 99 more times. Fun, eh??? No, seriously, it’s fun. Of course, the room is mostly full of people madly scribbling out multiplication on paper.
• There was that usual unfolded polygon prism section, like, “which of the unfolded shapes shown equates to the 3D rendering in the picture?”…and other related spacial analysis.
• I can’t remember any other sections (there were at least ten or twelve), but short of having you solve mazes this test had everything.

Throughout the whole thing, I was excited and sweating – I was getting a real thrill out of it. Good times

Needless to say, I’ve never had another interview like that.

You know, I’d love to hear your own stories of crazy interview tests…and that’s what the comment section’s for!