Data Structures Interview Questions

When preparing for a data structure interview, understanding the underlying questions and motivations behind the questions can give you a strategic edge. You might experience different types of questions, such as behavioral questions, situational questions, and questions about your background and experience. Practicing how to answer different questions can build your confidence and prepare you to showcase your best self during the interview process. 

10 common data structure interview questions 

Want to ace your data structure interview? Read on to explore common interview questions and how to design your answers in strategic and effective ways.

1. What is your educational background?

What they’re really asking: How have you prepared academically for a career in programming?

When going into an interview of any type, you should plan to provide a brief overview of your education and how you learned the skills needed to perform well in the role. This type of question is popular at the beginning of interviews, as it helps the interviewer immediately assess your communication skills and enthusiasm for the position. 

When answering background questions like this, you should speak about specific experiences and projects within your education that have helped you build a solid foundation in programming and data structures. While your response should detail your degrees, you should also elaborate on specific coursework and projects highlighting relevant skills that make you a great candidate for the position.

Other forms this question might take:

• Tell me about yourself.

• How have you developed the skills needed for this role?

2. How do you approach a new data structure or coding process?

What they’re really asking: What’s your approach to problem-solving in coding?

With this question, interviewers want insight into how you plan and execute new projects. It is a behavioral interview question, which means interviewers design it to let them determine your future job performance based on your past behavior. 

You can use the situation, task, action, resolution (STAR) method to answer this question. Start by clearly defining the environment in which you receive a new project. Next, elaborate on your responsibilities and tasks within the project, your actions to organize and complete these tasks, and the final outcome. Answering this way helps bring the interviewers through your entire thought and action process when given a new data structure or coding process and shows them why your methods effectively lead to the desired end product.

Other forms this question might take:

• What is your thought process when approaching new projects?

• What are your first steps after receiving a new project?

3. What is your experience in programming?

What they’re really asking: What level of practical expertise do you bring to the job?

When talking about your experience in programming, you will want to be specific about what your role was within each project, give examples of how you contributed, and state which skills you utilized or learned throughout your experiences. 

Discuss the duration of your programming career, but highlight the variety and depth of your experiences, including projects that have significantly contributed to your growth as a programmer. If you worked on programming projects outside of professional roles, such as contributing to open-source projects, this is a great time to speak about that.

Other forms this question might take:

• How long have you been a programmer?

• Tell us about your previous projects.

4. How would you explain data structures to those unfamiliar with them?

What they’re really asking: Can you simplify complex concepts for non-technical listeners?

While your primary responsibilities are likely to be technical, coding professionals often must communicate their work with people from various backgrounds. This question tests your ability to share your work with diverse audiences and highlights how you might communicate with non-technical team members. 

When answering this question, focus on breaking down data structures into their basic concepts and uses while avoiding technical jargon. You can use stories or real-world examples to make these concepts accessible to someone without a technical background, demonstrating your communication skills.

Other forms this question might take:

• How do you work effectively with people from non-technical backgrounds?

• How do you prefer to present your results to diverse audiences?

5. Why are you interested in this role?

What they’re really asking: Why should we hire you?

Interviewers ask this question to see if you understand the responsibilities of the role you’re applying for, whether you are passionate about the company and position, and whether your short and long-term goals align with their expectations.

To answer this question effectively, you should research the position thoroughly and fully grasp what your job responsibilities would look like. You should structure your answer to include information about how the position fits your career goals, how you will contribute positively to the organization, and specific details about the role that make it a uniquely good fit for your skill set.

Other forms this question might take:

• Why do you want to work here?

• Why did you apply for this position?

6. What is a binary tree?

What they’re really asking: Do you understand fundamental data structures?

Your interviewer may ask you fundamental data structure questions to assess the breadth of your knowledge. Binary trees are a type of data structure in which each node has between zero and two children (descendant nodes).

You can use several types of binary trees, including rooted binary trees, full binary trees, and perfect binary trees. Knowing when to use each tree type and how they help reflect structural relationships within data can help showcase your knowledge of basic structures.

Other forms this question might take:

• How did you utilize binary trees in past projects?

• What is your decision-making process for choosing the type of binary tree to use?

7. When should you apply a binary search?

What they’re really asking: Can you choose the right tool for the job?

When asking about binary searches, your interviewer likely wants to assess how well you can quickly manipulate large data volumes and find needed information. This is an essential operation within computer science and critical in implementing many algorithms.

Binary search essentially searches a list to find a specific value. It’s effective when dealing with a sorted array or list when you need to find the position of an element quickly. This technique is known for speed and significantly reduces the search interval with each step, making it especially useful when focusing on efficiency.

Other forms this question might take:

• How do you effectively retrieve information from your data?

• How would you find the fourth smallest value in your search tree?

8. What operations can be performed on data structures?

What they’re really asking: Do you have a solid understanding of data structure fundamentals?

Your interviewer assesses whether you can effectively manipulate data within your data structure. As you need to edit, sort, or access information, you will need to know what types of operations you can perform on your structure.

Each data structure performs operations differently, and you will optimize these for specific characteristics. Examples of everyday operations include inserting or deleting information, traversing a data set, or searching for particular terms.

Other forms this question might take:

• What is your understanding of effective data management?

• What types of operations have you performed on your data structures in the past?

9. Can you rearrange positive and negative values in an array?

What they’re really asking: Can you solve practical coding problems?

This question tests your ability to apply algorithms to solve array manipulation challenges efficiently. One approach to answering this question is using a two-pointer technique, moving one pointer from the start to another from the end. You then swap values to rearrange positive and negative numbers without using extra space. 

Other forms this question might take:

• How do you merge two sorted arrays?

• How do you find the minimum value in an array?

10. How do you stay up to date on your technical skills?

What they’re really asking: Are you committed to continuously learning new skills?

Technology is a rapidly evolving field, and you will likely find yourself in positions where you need to update your skill set. When answering this question, speak about online courses, blogs, podcasts, seminars, or bootcamps you regularly attend to keep your knowledge updated.

This question offers an excellent opportunity to share how you have recently learned and applied a new skill to your projects.  

Other forms this question might take:

• What is a skill you learned last year?

• What is your chosen way to learn about recent developments in this industry?

What does a data structure professional do? 

Data structures are a vital component of many professions within the data science and computer science fields, including those who design, implement, and optimize data structures. Doing so allows them to solve complex data management problems, including how to alter and search for data. They analyze the requirements of a system or application to determine the appropriate data structures for each use case.

You can expand your opportunities across data-driven fields by effectively showcasing your knowledge of data structures within an interview. 

Jobs in data structures

Because data structures are relevant within many data science professions, you can choose between several career options when searching for a role that uses knowledge of data structures. To work directly with data structure algorithms, consider exploring positions like the following, each listed with its average annual base salary according to March 2024 data.

• Data architect: $134,225 [1]

• Big data engineer: $130,110 [2]

• Data modeler: $115,619 [3]

• Database developer: $113,540 [4]

• Database administrator: $100,749 [5]

Tips: Acing your data structures interview

Interviews can feel daunting, but with the proper preparation, you can use this time to gain deeper insight into the company, position, and whether it’s the right fit for you. Remember these tips to stand out and maximize this real-time company exposure, whether it's your first interview or not.

• Research the company and position.

• Practice providing structured answers to common questions.

• Ask questions if you don’t understand a prompt.

• Don’t focus on mistakes. Keep moving forward with the next question.

• Show your passion for your work.

• Slow down your answers and take time to think through your response.

• Be prepared to explain how you thought through each answer.

• Familiarize yourself with different question types (e.g., situational, behavioral).

Start learning with Coursera.

Data structures are a fundamental concept within computer and data science, making them a popular topic for technical interviews across professions. To ace your interview, taking time to learn about different types of questions, preparing mock answers, and keeping top tips in mind can help you showcase your skills effectively. For additional preparation, take Meta's Coding Interview Preparation intermediate course for structured guidance and practice. You may also get more in-depth generalized interviewing knowledge with options like Advanced Interviewing Techniques from the University of Maryland, College Park.