Computer science is one of the most lucrative and rewarding fields in the working world. But before you land that great CS gig, you have to go through the application process. That’s why we’ve put this guide together: to help you prepare for the most common computer science interview questions.
Overview of Computer Science
With the tech industry growing rapidly, Computer Science has become a popular career choice for many students. Common roles Computer Science graduates apply for are: Computer Science Engineer, Computer Science-IT Engineer, Software Development Engineer, IT Software Developer, and Applications Engineer.
Computer Science is one of the top-earning bachelor’s degrees among engineering, math, science, and business. As a Computer Science graduate, you can earn an average salary of $50-$130k per year. In this field, you will also have a lot of growth potential as computer scientist salaries are known to increase dramatically year over year.
Technical Computer Science Interview Questions
To help you with your interview process, we have gathered tips and suggestions that you can use to ace your interview. Here is a list of some common computer science questions that can help you perform well in your next interview.
In a computer science interview, your answers to the general and technical questions will be a major factor in your selection for the role. Most of the questions will be based on coding, programming languages, operating systems, computer hardware and software, and other computer system topics.
These are the sorts of questions that establish baseline knowledge. For example, what is a class/superclass? What is an object? What is a file? Linked list, class variable, multiple inheritances, base class, input and output, conversion constructor, object oriented programming, etc.
Let us take a look at some similar technical interview questions and answer the above.
Which programming languages do you prefer and why?
This is a very basic question and you should know that there is no right answer to it. If the role you are applying to requires knowledge of a certain language, you can mention some things you like about that particular language. Or you can mention the language you prefer and give the reason for your preference for it. For example:
What is a class and a super class?
The answer to this question and similar others should be at the tip of your tongue. You can answer this question in the following way:
A class defines the blueprint from which class objects are created. For instance, the characteristics of an object, and what methods and variables is it associated with. A super class, on the other hand, refers to the direct class under consideration.
What’s the difference between Process and Thread?
While a process and thread may seem similar in concept, both are independent sequences of execution. You can answer this question as follows:
Process is a program in execution. Thread is a segment of a process which means a process can have multiple threads.
Compared to a thread, process takes longer to terminate. Process also takes longer to create while thread takes a shorter time. Process is isolated while threads share memory.
What is a constructor?
In object-oriented programming, a constructor is a special method of a class or a structure and initializes an object of that type. Your answer can go somewhat like this:
A constructor consists of methods used to create or prepare an object of a class. A default constructor accepts arguments to set required member variables.
Most of the CS interview questions as covered above will revolve around similar concepts.
Common Computer Science Interview Questions
- What is a message?
- What is a stream?
- How many types of access modifiers are there? Name and define each one.
- What is the application layer?
- Name the main types of constructors.
- Explain some main types of access modifiers.
- What is the transport layer?
- What is the difference between an interface and an abstract class?
- Describe a singleton class.
- What is an abstract class?
- What is an abstract keyword?
- Provide some C source code.
- What is a byte stream?
- Name a type of balanced binary tree. Explain how it is implemented.
- What is a view?
- How does the central processing unit (CPU) function within a computer system?
- What is GitHub, and how do you use it?
- Explain how a wrapper class works.
- What is an array?
- What is an operating system? Give some examples of common operating systems in use today.
- Comparison between method and constructor.
- What is a data structure?
- List the steps for creating an object.
- Explain the purpose of the data link layer.
- What is recursion?
- Explain the difference between overloading and overriding.
- What do you know about the software development cycle?
- What is polymorphism?
These were some examples of technical interview questions that you can expect in your next interview. The best way to prepare would be to review basic CS concepts first. Then, start comparing concepts, identifying similarities and differences, and understanding the structure and components involved in each concept. You should also check websites like Glassdoor for the types of questions that the previous candidates were asked for a similar role.
If you are in an in-person interview, the interviewer might ask you to answer questions on a whiteboard. These whiteboard interview questions often ask you to solve programming problems in real time. In a phone interview, however, the focus will be on the delivery of your understanding of concepts and their application.
Behavioral Interview Questions
While preparing for a computer science interview, don’t assume the hiring manager will only ask the technical questions. Behavioral interview questions have become a huge part of the hiring process at most companies. That goes for tech giants as well as startups.
Behavioral questions are usually phrased like this:
- Tell me about a time when…
- Describe a situation when…
- Give me an example of a time…
The purpose of the behavioral questions is for the employer to understand the results you achieved in your past work experience. For example how you applied your knowledge and skills from your previous job(s) to take a concrete ‘action.’ This action can be a task you completed successfully, a team you managed or a real-world problem you solved.
The interviewer might ask general questions as well. For example:
- What are your greatest strengths and weaknesses?
- Describe a situation when you would seek help on something you didn’t understand. Then, describe a situation when you would find the solution on your own. Why?
- Why are you leaving your current role?
- Why are you applying for this role?
- How do you handle multiple projects?
- Tell me about a time when you disagreed with a coworker. How did you handle the situation?
Be sure to go over your resume multiple times before the interview so you can answer any questions related to the resume as well.
Ask Questions of Your Own
The hard part is over; however, this last part which many people tend to not pay much attention to is also very important. In this last step, you can show the interviewer that you are interested in the position and were attentive throughout the interview process.
So at the end when an interviewer asks, “Do you have any questions for me?” you should always have a list of 2-3 questions. You can ask a follow-up question based on the job description or inquire about the team.
Interview preparation is not an easy process. It requires time and dedication. And this is especially true when it comes to preparing for computer science interviews. Each company has a different way of interviewing. You can look at sample interview questions for the role on sites like Glassdoor. This way, you can get a sense of what kinds of questions could come your way.
Also, make sure to follow up on the hiring process after the interview. If you don’t hear back from the hiring manager in a few days, you should contact them and ask for updates. This shows them that you are still interested in the position and are someone who knows how to take initiative.