10 Essential Computer Science Interview Questions and Answers

Dana Guterman
Updated: August 8, 2023

If you major in computer science, it’s unlikely you’ll ever wonder what to do with your degree. From software development to data science, those with a knack for numbers and a love for problem solving can pursue a variety of careers. It’s still a competitive market, however, so you need to be well prepared once you land an interview. Avoid getting a 404 page by reviewing our interview preparation resources. Then, read on for a list of the top 10 computer science interview questions and answers.

1. Tell me about yourself.

This ever-popular interview question is many an interviewer’s go-to way to kick off the interview, so practice your response ahead of time. The interviewer wants to get to know you—but they also want to know how your skills, experience, and strengths will create value for the business. Focus on relevant skills and accomplishments (but throw in a memorable detail or two), and keep your response to a minute or less. You can read more about this common question in our “Tell me about yourself” interview guide. Here’s a sample response to get you started:

“I recently graduated from ABC University with a degree in computer science, and I’m really excited about the prospect of working at your company. At school, I knew I wanted to work as a mobile developer from day one, so my coursework reflected that. Over the past three summers, I’ve interned with one start-up and two mid-size companies, which gave me the opportunity to work closely with their mobile developers and learn from them. I also have a lot of experience with online code repositories, and I love to contribute as much as I can. When I’m not coding, I love to draw my own comic books.”

2. How would other people/your colleagues/your boss describe you?

This is another common interview question that allows you to differentiate yourself from the competition, share why you would be an asset to the company, and prove that you’re self-aware. The interviewer is checking on whether you have an accurate picture of yourself, so a good response might include two positive traits and one “needs improvement.” Back up your response with evidence and show your personality.

“Clients often tell me that I’m a good communicator because I’m always able to articulate people’s needs. They’re very impressed by how I’m able to pick up on subtle hints and nonverbal clues, and I believe this has helped contribute to my success. My last boss told me that I’m a great problem solver, but can also be too structured. I think that comes from my background in computer science, where—as you well know—you’re solving problems all day, and you need to stay super organized. I’ve started doing yoga to loosen up a little!”

3. Tell me about your most significant accomplishment.

Interviewers like this question because it clues them into your work patterns, your actual performance, as well what matters most to you. Set up the situation, then go into detail about your actions and the impressive results they yielded. This question calls for specific stories, so you’ll benefit from using the STAR method. Take advantage of this question and really let yourself shine:

“When I first started at my internship, the onboarding process wasn’t very thorough, and the initial training for developers left a lot to be desired. After sharing my concerns with my trainer, she agreed that I could form a sub-committee to restructure the program. Over the next two months, I developed better resources for new employees and stronger mentorship program. I feel like this showed my initiative and my problem-solving abilities.

4. What is your greatest strength?

With this common interview question, it’s important to frame your answer in the context of the prospective company’s unique needs and how your strength can help to meet them. Ensure your chosen strength is work-related and relevant to the position. Then, support it with evidence by including specific anecdotes or accolades related to your strength.

“I’m highly motivated and extremely passionate about developing. Everyone knows me for completing projects ahead of deadlines, and I feel this is especially important in our field, where things are constantly evolving and changing. I take the initiative and always come up with various ways to solve a problem without needing to wait for direction. I was the go-to person for last-minute projects at my internship because I could always turn a project around within 24 hours.”

5. What is your greatest weakness?

The key here is to choose a weakness that isn’t a true deficiency and isn’t vital to the job at hand. You’re in computer science, so don’t say that you’re bad with numbers. Furthermore, answers like “I’m a perfectionist” are overplayed and feel disingenuous; instead, be honest, and focus the majority of your response on what you’re doing to address your shortcomings and improve. You can read more about this popular, tricky question here.

“I would say my biggest weakness is that I’m a recent graduate, so I don’t have a lot of work experience. However, I’m a fast learner, and I’m highly adaptable, so I’m confident that I’ll build my skill set quickly once I start working full-time. I’m up to speed on the latest programming trends, and I pride myself on bringing a fresh perspective. I’ll bring my strong work ethic and commitment to my job—every single day.”

6. Tell me about your preferred programming languages. Why do you prefer them?

You’re interviewing for a computer science job, so it makes sense that an interviewer would ask this question. The good news is that there’s no correct answer here. You may want to research the company beforehand to find out their favorite languages, but if you aren’t fluent in them, don’t lie! Simply choose what you’re the most comfortable with and own it, and highlight that you’re excited to learn other languages in the future.

“My preferred programming language is Python because it’s easy for a beginner to pick up, and it has a lot of excellent libraries. The support libraries greatly reduce time spent on coding, and I find it helps me be efficient, but also allows room for creativity. I love learning new languages, though, so I’m excited to pick up new ones in the future.”

7. What is a class? A super-class?

As with any interview that requires hard skills, there will be multiple technical questions to assess your general knowledge and familiarity with common terms and topics. For this question, you might answer:

“A class defines the characteristics of a certain type of object, such as which messages they’ll respond to and what form of response they’ll take. On the other hand, a super-class is the basis of the class under consideration.”

8. What is a default constructor? What is a conversion constructor?

As you prepare, be sure to review basic concepts and refresh your memory about important skills and subjects that could be included in the interview.

“A default constructor either has no arguments, or all of the arguments have default argument values. A conversion constructor accepts one argument of a different type and uses this as a way to infer conversion rules for a class.”

9. How are C and C++ different ? Would you prefer to use one over the other?

You’ll definitely want to brush up on common programming languages prior to your interview. While there is no right answer for a question like this, the interviewer is assessing your knowledge and checking that you can compare and contrast the two languages. You might answer something like:

“C++ supports the object-oriented programming paradigm, while C is based on structured programming. I prefer C++ due to its object-oriented nature, and also because you can build almost anything with it.”

10. What is multiple inheritance? What are its advantages and disadvantages?

Being able to explain common topics and point out their advantages and disadvantages will be critical to your interview. Questions like this test your knowledge and critical-thinking skills.

“Multiple inheritance is the process where a subclass can be derived from more than one super-class. Its advantage is that a class can inherit the functionality of more than one base class, but its disadvantage is that it can lead to a lot of confusion when two base classes implement a method with the same name.”


Computer science is a broad field, with many possible career paths, but if you know the answers to these 10 questions, you’ll be wired for success.