Surviving the Technical Interview

by Deb Shinder

SWatch Reader Favorite! It seems there is no quicker way to strike terror in the heart of an IT professional (or aspiring IT pro) than to speak those ominous words:'First, you'll need to pass a technical interview.'

It seems there is no quicker way to strike terror in the heart of an IT professional (or aspiring IT pro) than to speak those ominous words:

"First, you'll need to pass a technical interview."

I've had students who were at the top of their network training classes call or write to me in a panic, asking what to expect. As if a job interview weren't nerve-wracking enough by itself, when you add the word "technical," it becomes a whole different - and even scarier - prospect. This article will, I hope, help you to overcome your fears and doubts about the process and tame the tech interview beast.

Before I get into the how-to's, though, I have a confession to make. Even though I've sat on the other side of the interview desk on many occasions as the hiring authority, even though I enjoy the chess-like game of strategy of the job interview situation, even though I am - after building a highly successful IT business along with my husband, teaching hundreds of students in computer-related courses, and with eleven IT books published - pretty confident of my skills and knowledge, I still dread the "technical" interview.

Technical Interview Facts of Life

But it's a fact of life in this industry, so it's important to learn our ways around the tech interview, anticipate some likely questions (or types of questions) that we'll encounter, and understand what the technical interviewer is really looking for (contrary to what you may feel during the interview, most are not sadists who stay up nights thinking of new ways to torture job applicants with obscure and convoluted interrogatories).

Revised, Dec. 20, 2010

The Purpose of the Technical Interview

The purpose of the technical interview is ostensibly to evaluate your level of knowledge or skill in the topic areas relevant to the position for which you're being considered. However, there's more going on in most interviews than that. In reality, as you struggle to explain the differences between DHCP and BOOTP or frantically search your memory for the best definition of "asynchronous," your interviewer is likely to be judging you on any or all of the following:

  • First and most obviously, how much you know about the hardware, operating systems, applications, and networking technologies with which you would be working
  • How articulate you are, especially for a position in which you may be called upon to wriemte reports or documentation, or give presentations to users or upper management
  • How poised and personable you are, especially in a position like tech support or network administration, where you will have to deal with many people at all levels of the organization
  • How well you handle stress, especially if the position is in a high-pressure, time-sensitive environment
  • How innovative you are -- can you "think outside the box" to come up with new solutions rather than just spout the party line of the moment
  • Whether you've had hands-on experience with the products, or you only know the "factoids" you read in books or learned in a classroom
  • How vendor-centric you are -- do you know only one product line (e.g., Windows or VMware) or do you have a broader base of knowledge that is necessary in today's modern hybrid network environments.
  • How willing you are to take on extra duties or work overtime when necessary; how much pride you take in your work and in doing a good job.
  • How well you balance ambition and leadership with the ability to follow the instructions and defer to the wishes of management, even if you disagree.
  • How loyal you'll be to the company.
  • How honest you are (including whether you're able/willing to say "I don't know" when you don't know the answer to a question).
  • Whether you have the wherewithal to find out the answers to those questions and the solutions to those problems that you don't know.

Wow. That's a whole lot of evaluating going on. No wonder technical interviews make people so nervous.

Now that you're aware of some of the underlying purposes of the interview, you should go through the list, and consider how you can tailor your answers to positively impact the interviewer's impressions in each of these areas. Obviously, "knowing your stuff"is mandatory, but that alone is not enough to get you through the interview with flying colors.

Practice Makes Perfect at the Technical Interview

Practice your interview skills with a technically-savvy friend or ask yourself questions and then practice your answers in front of a mirror. Videoing your practice interviews can be an extremely useful aid. Although you may be embarrassed the first time you watch yourself,you may be amazed at the little nervous gestures or speech habits (for instance, a peppering of "you know"s or "I mean"s or "umm"s you weren't aware of before.

As you review the recording, ask yourself questions like the following:

  • How enthusiastic do you seem? Do you project an image of someone who really wants the job?
  • Does your body language send undesirable signals (e.g., slumped posture that indicates laziness or sloppiness, or shifty eyes that might be interpreted as a sign of dishonesty)?
  • Do you respond clearly and confidently when you know the answer to a question?
  • If you don't know the answer, do you say so in a straight forward manner, without being overly apologetic or appearing perplexed -- and then tell the interviewer what steps you intend to take to go about finding the answer?

Once you've identified the problems, you can work on correcting them. Make additional recordings so you can see your progress. As you watch, ask yourself honestly whether you would hire yourself based on the impression you make in the interview.

Unfortunately, your actions and words and personality are only one part of the equation, and whether they add up to a job offer or rejection may also depend in part on the personality of the person conducting the interview.

Revised, Dec. 20, 2010

Types of Questions Commonly Encountered in the Tech Interview

A technical interview typically goes beyond the usual "tell us about your background and experience" of a regular job interview. It may also include questions that have nothing to do with computer hardware and software, designed to measure your logic, reasoning and general problem-solving skills. Some of the biggest IT employers are notorious for this tactic, and it's these "brain teaser" questions that often throw the inexperienced interviewee for a loop.

Why are Manhole Covers Round? and Other Logic Questions

Famous (or infamous) examples include such questions as "why are manhole covers round?" (Because a round cover with a lip cannot fall into the manhole. A square cover could be turned diagonally and dropped into the square hole).

Many of these are more involved, such as the old "fox, chicken and grain" scenario that goes like this: A man has a boat and wants to transport a fox, a chicken and a bag of grain across a river. There can only be one item in the boat with him at a time. He can't leave the fox alone with the chicken, or the chicken will be eaten. He can't leave the chicken alone with the grain or the grain will be eaten. How does he get them all safe and intact to the other side? (We'll provide the answer at the end of this section.)

Many technical job candidates come out of interviews mumbling "what in the heck do foxes and chickens have to do with administering an Ubuntu/Windows/Solaris network?" Believe it or not, your ability to analyze a problem such as the one in the scenario, mentally evaluate your options, and come up with a solution has a lotto do with network administration. If you can't think through and apply logic to a simple non-technical fox and chicken problem, how much more difficult will it be to troubleshoot problems that also require extensive technical knowledge?

Luckily, numerous books and websites can provide you with practice for these brainteaser/logic tester type questions. One good place to start is with http://www.brainteasers.net/.

You Don't Have to be Correct to be Right

In addition to logic questions, you will probably be grilled quite intensely about specific technical topics. If you have an IT certification such as MCSE, CNE, or CCNA, your interviewer will probably be looking for answers that show you've done more than the "right answers" for the certification exams. In fact, a savvy interviewer will use his or her knowledge of the exam questions to try to trip you up.

The key here is not to try to pass yourself off as having more experience than you really do. In today's tight job market, people with "paper certs" do get hired -- and if they've been honest upfront about their experience level, they can get valuable training and work their ways into excellent, high-paying positions. On the other hand, those who misrepresent themselves often get thrown into situations they can't handle and end up being let go. Remember that one of the things your interviewer may be evaluating is how honest you are. Nobody is eager to hire a liar.

Treat the Technical Interview Like an Exam

However, it's not dishonest to do all you can to present yourself in the best light possible. And it's not dishonest to study for your technical interview. Review technologies with which you're less familiar, if you think they may be discussed in the interview. For example, if you've been working for three years in a pure Microsoft environment, and you expect the technical interview to include some questions about Linux or UNIX, there's nothing wrong with refreshing your knowledge by reading books about those technologies before the interview. If you can get your hands on a Red Hat or UNIX box and do a little hands-on practice, that's even better. The more comfortable you feel with your level of knowledge and skill, the better you'll come across in the interview.

Revised, Dec. 20, 2010

Answer to the Fox and Chicken Dilemma

The answer to the fox and chicken dilemma is really very simple, but many people puzzle over it endlessly because of their one-way mode of thinking. Here's the solution:

The man takes the chicken across first, leaving fox and grain together on the other side. He returns and gets the fox, but when he deposits the fox on the other side, he takes the chicken BACK across, so that the fox and chicken aren't left alone together. He drops the chicken off back on the other side, picks up the grain, and takes it across to deposit with the fox.

Finally, he returns to retrieve the chicken and takes it to the other side.

At no time were the fox and chicken left alone together, nor were the chicken and grain.

At no time was more than one of them in the boat with the man simultaneously.

The reason this puzzle is so difficult for many people is that it never occurs to them that they can take something back once they've transported it to the second side. Your ability to solve this puzzle demonstrates a willingness to think "outside the box" and come up with creative solutions that still fit within the specified parameters.

Revised, Dec. 20, 2010

Tips and Techniques for Surviving and Succeeding in the Technical Interview

Although it's fine to review some of the technical facts the night before your interview, staying up all night trying to "cram" is not productive. You should get a good night's sleep so you'll be fresh and awake and your brain will be working properly during the interview. Other do's and don'ts include the following.


  1. Be on time for the interview. "On time" means don't be late, and don't be significantly early, either. It's best allow yourself plenty of time to get there, just in case you hit a traffic snag or have to take a detour. If you don't encounter problems and end up arriving far ahead of time (more than fifteen minutes), go find a convenience store and have a cup of coffee, or wait in your car for a while. While tardiness is a pet peeve of interviewers, most are just as put off by the candidate who comes in much earlier than scheduled and sits around in the reception area looking impatient.
  2. Dress appropriately. Appropriate dress for an interview is not necessarily the same as appropriate dress for work after you get the job. Just how formally you should dress depends on the company atmosphere and the position and demeanor of the person who's interviewing you. It might be appropriate to dress up more if your interview is with the company president, than if it's with an "in the field" tech manager. It's better to err in the direction of too conservative than to dress too casually, but if you overdress too much (i.e., you're much more formally dressed than the interviewer), you may come across as stuffy and lose points. If you've researched the company and interviewer beforehand, you'll have an idea of what type of dress is most appropriate. That brings us to the next "do."
  3. Do your homework. Many, many candidates go into interviews -- technical or otherwise -- "flying blind." If you don't care enough to find out about the company so you can talk intelligently about why you want to work there, why should the interviewer care enough to hire you?
  4. Follow up after the interview. The end of the interview is not the end of your candidacy (unless you really bombed, and even then a good follow-up can sometimes turn things around). I have been told personally several times in my working life that the reason I got a particular job was because I was the only candidate who sent a follow-up "thank you" note to the interviewer, restating my interest in the position. It takes about five minutes and costs only the price of a postage stamp (and this is one instance where snail mail makes a better impression than email), and it can make the difference between coming out on top or getting that "we are sorry that your talents don't fit our needs" form letter.


  1. Overwhelm the interviewer. It's great to be enthusiastic, but don't bubble with enthusiasm -- you want to convey a quiet, professional sort of enthusiasm that.
  2. Ramble. Answer the interviewer's questions thoroughly and in appropriate detail, but don't veer off the topic to attempt to demonstrate everything you know about everything. Make your answers as concise as possible.
  3. Answer in monosyllables. For example, "have you worked with DHCP?" is not, despite appearances, a simple yes/no question. The interviewer expects you to follow your "yes" with examples of how you've deployed DHCP in a routed network, or how many DHCP servers you've configured, or how you implemented a DHCP superscope on a multinet. If you must answer "no," you should add (if true) that although you haven't had a chance to work directly with DHCP yet, you have studied the topic and know x, y and z about the protocol and when and how to use it.
  4. Let one mistake cause you to give up on the interview. Everyone makes mistakes, but some candidates will stop trying if they realize they've answered a question incorrectly or incompletely or didn't know the answer at all. If the interviewer corrects you, accept it gracefully and tell him or her that you appreciate the opportunity to learn something new. If you realize you've bungled a question but the interviewer doesn't mention it, you may want to bring it up at the end of the interview: "you know, I just realized that when I answered (whatever the question was), I was thinking about something else. A better answer to that would have been ..." This lets the interviewer know that you really do know the correct answer, and that you're honest enough to admit it when you make a mistake. Because employees who try to hide, cover up or deny their mistakes can be costly to a company, most interviewers will appreciate this quality.

This article has been based on the premise that your tech interview was of the on-site, in-person variety. However, there is another type of technical interview, conducted over the phone. Some of the tips we've given will be the same, but in some aspects, the telephone interview is different. We will discuss those differences next.

Revised, Dec. 20, 2010

Telephone Interview vs. In-person Technical Interview

You might think that having your technical interview over the phone would be easier than doing it in person. After all, you don't have to worry about under- or overdressing.

In some ways, it is easier -- but you also lose some of the advantages of the face-to-face interview. Most crucial is the inability to observe the interviewer's body language for clues to his/her demeanor. Remember how we said up to 80 percent of what is communicated is based on body language? It's difficult to gauge the response to your words when you can't see the interviewer. One result is that you must be much more careful about using humor, or deviating from the subject. You won't have the interviewer's physical reaction to signal you that it's time to get back on track.

Expect the Unexpected

Another problem with the telephone interview is that it may occur unexpectedly. Many interviewers are courteous and will set up a specific time to call, but some will surprise you, phoning and wanting to do the interview right now, at a time that may not be optimum for you. This can be disorienting and even cause your mind to go blank.

You may think that if you're interviewed by telephone, it will be easy to cheat. You can have the books or your computer in front of you and look up the answers to questions you don't know. You'll probably find, however, that it's very difficult to do this without the interviewer knowing. Unless you know ahead of time what the questions will be and have your books and website marked and ready, it's going to take too long to look up answers for you to pretend you're not consulting a reference. And, of course, if you know the questions ahead of time, you can go ahead and learn the material and not have to look it up during the interview.

Dress for Your Telephone Interview

Finally, although a telephone interview may seem less formal and less intimidating than an in-person interview, it is just as important that you prepare for it, and that you present yourself well. To hire or not to hire -- it's not uncommon for that decision to be made based on a telephone interview. At the very least, the telephone interview will determine whether you advance to the next step, which is usually an in-person interview. And the first impression that you make on the phone can pave the way to make that next step smoother, or it can be a difficult obstacle to overcome.

I have attempted to give you a very insights into the technical interview process in this article. I'll provide a few resources and suggestions for how you can obtain more information on this very important subject next.

Revised, Dec. 20, 2010

Summing it Up: Survival of the Fittest

Surviving and thriving in the technical interview is both an art and a science. Interviewing is a skill, and as such, the more you do it, the better you'll get.

A few resources to help you along the way include:

Ace the Technical Interview, by Michael Rothstein, published by Osborne/McGraw Hill. Includes updated information about Java, Visual Basic, UNIX, PowerBuilder, Oracle, and other technologies.

Finally, remember that if you don't get a job offer as a result of this interview, it doesn't mean the time was wasted. Consider it a learning experience. After all, many people pay good money for practice exams that allow them to get familiar with what the experience of taking a certification exam will be like. You got this practice interview for free -- and if you're smart, you'll analyze it and use it to help you prepare for the next one.

Revised, Dec. 20, 2010; Original date of publication, 9/18/2003

This article was originally published on Monday Dec 20th 2010
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