Interview Questions—memorable times on both sides

As I travel this week for TI’s university recruiting I think back on some memorable interviews—ones on both sides of the table. One still haunts me. I was seeking my first industry job, one that I desperately wanted but was not offered. I’ve long wondered whether the way I handled a particular technical question made a difference. I’ll get to that question in a moment.

Through the years I’ve seen various articles on interview questions for engineers. Some are tricky puzzles, guaranteed to torment. Others are checks on basic skills. Working through the questions can be a good tune-up for the interviewer, too. A recent blog on EDN’s site had an interesting interview question for op amp devotees. Check it out.

I’ve had some spirited discussions on interviewing philosophy through the years. One of my most respected and highly technical colleagues insists that a successful candidate must be able to answer specific questions on the internal workings of op amps. I’ve used a similar approach in the past but I’ve turned a different direction. I now prefer to find an area that the candidate thinks s/he knows best, then judge the depth and maturity of that knowledge with some questioning. My assumption is that, given exposure to our products and technical issues, they would soon develop a similar depth of understanding. We develop interviewing approaches that suit our personal style and sense of what works.

I often ask a candidate whether they repair things—a car, bike, computer, motorcycle, sewing machine… whatever. Having the confidence to say, “I can figure this out” is something fundamental in a real engineer. Repairing things says that they practice being an engineer in everyday life. A good sign.

An exhilarating feeling comes when I am able to teach a candidate something s/he doesn’t know—something that’s a bit surprising and gives new insight. At the moment the light bulb comes on (if it does), there is a strong connection between us. To me it says, “This person gets it and can grow.” To the candidate it says, “I’m going to learn at this place!” I’ve had engineers replay that moment to me much later in their career. An old mentor called that feeling a “psychic paycheck”—(thanks, Denny).

Our university staffing organization is super-organized this year, rolling out an interviewing method that will unify our approach across the company. Seems to make sense and we’ll see how it works. Still the technical portion of the interview is left to us, the technical wonks. That leaves plenty of latitude to argue about the best approach and come up with our own questions.

Okay, I promised to tell you the interview question that has dogged me for 41+ years:  You have a 1V AC source driving a 1Ω resistor in series with a 1Ω reactance capacitor. What is the AC voltage across the capacitor?

No, not 0.5V. I didn’t fall for that trap. But, eager to show that I was not intimidated by some basic phasor math, I calculated the amplitude and phase of the capacitor’s voltage and explained the result. After some reflection, I thought I could have answered very quickly in a way that would have demonstrated recognition and understanding. Can you guess how I thought I should have answered?

I bet you’ve had interesting interviewing experiences, perhaps on both sides of the table. Maybe you’re willing to share your favorite interview question, experience or philosophy in comments below.

Thanks for reading.

Bruce        thesignal@list.ti.com

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