3 Common Computer Science Job Interview Questions — And How to Rock Them

After you interview for a few computer science positions you start to see patterns. There are certain questions that come up every time, and you can take steps to prepare for them ahead of time.

To find out what questions employers will ask and how you can best answer them, we reached out to Tammy Colson, CEO at TalentCrib, a recruiting consultancy in Cleveland. Here are three common questions she cites for entry-level computer science interviews, along with three great answers.


Interviewers will ask you to walk them through a project from start to finish so they can see how you approached a problem, Colson says. This tells them about your logic and thought processes, but it also tells them a lot about your technical skill level and whether it matches with this position.

For this question, you’ll need a few good answers ready to go, Colson says. If you’re interviewing for a Java position, you need to share a Java project, she says. The same goes for C#, .Net, etc. — your story needs to match the job. “When I get feedback from interviewers, they often say something like ‘She gave me an example in Java, but this isn’t a Java job. Sounds to me like she’d rather work with Java,’ ” Colson says. Don’t lose out on a good job because you didn’t prepare.

To rock this question, think of a few different types of projects you’ve done and be prepared to explain them in truly geeky fashion. They should be impressive, senior-level projects, not something like making a bunny hop across the screen, Colson says. Show how you solved a business problem. Explain variables, syntax and any external resources you used. This is the place to show off your technical knowledge and computer geek prowess. Rehearse each story enough that you remember the details, but not so much that you sound fake. Then tell that story in the interview in a way that shows off what you accomplished plus your ability to translate it into a conversational format, she says.


Sorry, but you can’t just put “computer science genius” on your resume and expect an employer to take your word for it. Most companies, especially larger organizations, will ask you to complete an online exercise or work through a problem on a whiteboard during your interview, Colson says. Beyond whether you get the right answer, this tells the company a lot about you: how you handle stress, how you approach obstacles, etc.

To rock this question, relax and take your time, Colson says. Remember, they’re looking for a reason to hire you, not a reason to eliminate you. Take the time you need to complete the task and do it well. A whiteboard task, she says, will typically be complex, but not obscure. There will likely be several steps involved, but it will be things you’ve studied in classes. Work through the logic and be prepared to explain your steps. And if you start to panic, ask if you can talk through it, she says. It’s fine to say “I’m not used to someone watching me, but since you’re here, can I talk through the steps with you?”


Colson says computer science majors are in such high demand now that it’s pretty common to get this question even in a first interview for an entry-level job. And it trips some people up because they aren’t expecting the money question so soon in the process — they haven’t done any research on pay, or the research they’ve done hasn’t differentiated between wages in Louisiana and those in Silicon Valley. Both of these are mistakes.

To rock this question, Colson says you should be prepared, be reasonable and be honest. If three companies offer you $60,000 to $65,000 and you’re holding out for $85,000 because that’s what a professor said you could make or that’s what Google pays, you’re missing the mark, she says.

Instead, do some research up front. Colson says she likes Indeed, Salary.com and Payscale for good salary data for various locations and positions. This will give you a ballpark figure. Then be honest with organizations you interview with. It’s perfectly acceptable to say “I’ve got two offers around $60K but I’d like to make $65K, or find an organization with better benefits.” And then let the recruiters and hiring managers do their jobs. “Don’t be afraid you’re going to leave money on the table,” she says. If they really want you and what you’re asking is reasonable, they will work to get you what you need, Colson says.