Sep 19, 2023

15+ Data Science questions to Prepare for your Interview

Data Science is one of the hottest job in the 21st century because it overlaps the field of Machine learning and Artificial Intelligence greatly. But to get this job is no walk in the park. One must be well versed with programming, math and statistics. Once you have mastered that you need to be able to shine in the Interview as well. But many of you don’t know the whole interview process so I’ll break it down into digestible steps along with questions and their interpretation.

Let’s start with the first step:

1. Initial Phone/Video Screening

Before meeting in-person your interviewer may want to conduct this to know the following questions: 

1. Question: Can you briefly walk me through your resume and highlight your relevant skills and experiences?

  • What they are really asking: They want to get an overview of your qualifications and experience on paper, and to check if they align with the job requirements
  • Key points to address: Highlight relevant skills, experiences, and accomplishments on your resume. Ensure that your resume clearly demonstrates your fit for the data scientist role.

2. Question: What motivated you to pursue a career in data science, and why are you interested in our company?

  • What they are really asking: They want to know if you’re genuinely interested in their company and role, and do you possess basic communication skills?
  • Key points to address: Express your enthusiasm for the company and the position. Showcase your ability to communicate clearly and professionally for this take a brief pause before answering a question that gives you time to formulate your answers.

2. Technical Interview

This round purely focuses on your understanding of data science concepts and their real world applications along with how to solve these problem with the help of programming languages.

3. Question: Please complete this coding challenge/exercise to evaluate your technical skills. How would you approach solving this problem?

  • What they are really asking: Can you apply your technical skills to solve real-world problems quickly.
  • Key points to address: Approach the technical assessment methodically, demonstrating your problem-solving skills, coding abilities, and understanding of data science concepts.

4. Question: Can you explain a complex data science project you've worked on in the past, including the problem, your approach, and the results achieved?

  • What they are really asking:  They want to know if you can explain your technical work clearly and show your depth of knowledge in data science.
  • Key points to address: Walk the interviewer through your past projects, emphasizing the technical challenges, methodologies, and results achieved. Showcase your expertise in machine learning and data analysis.

5. Question: What machine learning algorithms are you most comfortable with, and when would you choose one over another in a real-world scenario?

  • What they are really asking: As a data scientist you must have worked with the most common machine learning algorithm like linear regression, logistic regression, SVM (Support vector machine), Decision tree, Naive Bayes algorithm etc. Explain your choice of algorithm.
  • Key points to address: While explaining the algorithm you’ve worked on, highlight what problem you were trying to solve and why did you choose that algorithm over the others or if you’ve used others then what was their accuracy score regarding the problem. 

6. Question: Can you explain the Bias-Variance Tradeoff in Machine Learning?

  • What they're really asking: When interviewers ask about the bias-variance tradeoff, they are assessing your understanding of a fundamental concept in machine learning. They want to know if you can explain how this tradeoff impacts model performance and what strategies you would employ to strike the right balance between bias and variance.
  • Key points to highlight:
  1. Begin by defining bias and variance in the context of machine learning.
  2. Explain that high bias (underfitting) occurs when a model is too simple and doesn't capture the underlying patterns in the data, leading to systematic errors.
  3. Clarify that high variance (overfitting) happens when a model is too complex and fits noise in the data, resulting in poor generalization to unseen data.
  4. Discuss the tradeoff between bias and variance and how it relates to model complexity.
  5. Mention techniques to address bias-variance tradeoff, such as cross-validation, regularization, and model selection.

7. Question: What is the Curse of Dimensionality in Data Science?

  • What they're really asking: When interviewers inquire about the curse of dimensionality, they are testing your knowledge of the challenges that arise as the dimensionality of data increases. They want to know if you understand the implications of having high-dimensional data and the strategies for mitigating these challenges.
  • Key points to highlight:
  1. Define the curse of dimensionality as the problems and complexities that emerge when dealing with data in high-dimensional spaces.
  2. Explain how high dimensionality can lead to increased computational requirements, data sparsity, and difficulty in visualizing and interpreting data.
  3. Discuss the impact of dimensionality on distance-based algorithms, where distances become less meaningful as dimensions increase.
  4. Mention techniques to address the curse of dimensionality, such as feature selection, dimensionality reduction (e.g., PCA), and manifold learning.
  5. Highlight the importance of domain knowledge and feature engineering in managing high-dimensional data effectively.

3. Behavioral/Soft Skills Interview

8. Question: Tell me about a time when you had to work on a data project with a tight deadline. How did you manage your time and prioritize tasks?

  • What they are really asking: How well do you work with others, and can you handle common workplace challenges?
  • Key points to address: Share anecdotes that highlight your teamwork, time management, and communication skills. Explain how you approach solving interpersonal or project-related issues.

9. Question: How do you communicate complex technical concepts to non-technical stakeholders?

  • What they are really asking: When interviewers ask this question, they want to assess your ability to bridge the gap between technical expertise and effective communication. They are interested in understanding how well you can convey complex data science insights and findings to individuals who may not have a deep technical background.
  • Key points to address: Explain that you tailor your communication to the audience's level of technical understanding. Recognize that not all stakeholders have the same familiarity with data science concepts. Describe your approach of using analogies or metaphors to relate technical concepts to familiar, everyday scenarios. This can make complex ideas more accessible

10. Question: Can you describe a situation where you faced a significant data-related challenge on a project? How did you handle it, and what was the outcome?

  • What they're really asking: With this question, interviewers aim to assess your problem-solving abilities, adaptability, and how you handle challenges in a data science context. They want to understand your approach to overcoming obstacles and the impact of your actions on the project's success.
  • Key points to address:
  1. Challenge Description: Begin by describing the specific data-related challenge you encountered on a project. Clearly explain the context and the potential impact on the project's goals.
  2. Your Response: Detail the steps you took to address the challenge. Did you conduct additional data cleaning, modify your modeling approach, or collaborate with team members to find a solution?
  3. Outcome: Discuss the results of your actions. Did your efforts resolve the challenge? How did your actions contribute to the project's success or lessons learned?

11. Question: Can you provide an example of a project where you had to work closely with a cross-functional team (e.g., engineers, product managers, or business analysts)? How did you ensure effective collaboration, and what was the project's outcome?

  • What they're really asking: This question is designed to evaluate your teamwork and communication skills. Interviewers want to know how well you can collaborate with colleagues from diverse backgrounds and how you contribute to successful cross-functional projects.
  • Key points to address:
  1. Project Context: Describe the project where you collaborated with a cross-functional team. Highlight the roles of team members and the project's goals.
  2. Collaboration Approach: Explain how you ensured effective collaboration. Did you establish clear communication channels, set expectations, or coordinate regular meetings?
  3. Challenges and Solutions: Discuss any challenges or conflicts that arose during the collaboration and how you addressed them. Did you adapt to different working styles or find common ground?
  4. Project Outcome: Share the results of the project. Did the collaboration contribute to achieving the project's objectives? Were there any key takeaways or lessons learned from the experience?

4. Case Study/Project Presentation

12. Question: Please present a data science project you've worked on, including the problem statement, data preprocessing, model selection, and key findings. What were the business implications?

  • What they are really asking: Can you effectively present your work, communicate your thought process, and demonstrate your problem-solving abilities?
  • Key points to address: Clearly present your project, emphasizing problem definition, data preprocessing, modeling, and actionable insights. Don’t just crunch numbers instead engage the interviewer with your storytelling skills.

5. Team Fit/Company Culture Interview

13. Question: How do you approach collaborating with cross-functional teams, such as engineers, product managers, or business analysts, to achieve a common goal?

  • What they are really asking:
  • Key points to address:

14. Question: Why do you believe you would be a good fit for our data science team and our company culture?

  • What they are really asking: Every data team is different even though they might be doing similar things therefore as humans it’s our tendency to find out whether a candidate fits into a team’s dynamics and align with their company's values and culture.
  • Key points to address: Discuss your collaboration skills and your ability to adapt to different team dynamics if you don’t have job experience you can always site your college project collaboration or any open source project work. Then to find out whether you are a good fit for the company or not you need to visit the company’s website or social sites like Instagram/ Twitter/ LinkedIn to research the company culture and see how you align with its values.

6. Reference Checks

15. Question: Can you provide references who can speak to your work as a data scientist? What would they say about your strengths and areas for improvement?

  • What they are really asking: Can your previous colleagues or supervisors vouch for your skills, work ethic, and character?
  • Key points to address: Provide references who can speak positively about your technical competence, reliability, and teamwork. Ensure your references align with the requirements of the role.

7. Final Interview/Negotiation:

16. Question: What are your salary expectations, and what other benefits or considerations are important to you in this role?

  • What they are really asking: Express your commitment to the role and the company and be prepared to discuss your salary expectations and other benefits you value. 
  • Key points to address: 
  1. Begin by explaining that you've conducted research to understand the market value of similar roles in the industry. Mention specific sources like Glassdoor, Indeed, or, which you used for your research.
  2. Emphasize how your level of experience and expertise align with the responsibilities and requirements of the role. Mention any relevant certifications, skills, or achievements that justify your salary expectations.
  3. Express your genuine interest in the company and the role, highlighting how your skills and background make you a valuable asset to the team. This shows your commitment to the position.
  4. Provide a salary range rather than a specific number. This allows for flexibility in negotiations. Ensure that the lower end of the range is within your acceptable salary range.
  5. Discuss other benefits or considerations that are important to you. This may include health insurance, retirement plans, stock options, flexible work arrangements, professional development opportunities, or any unique offerings the company has.
  6. Mention that you are open to a constructive discussion and negotiation. Reiterate your eagerness to join the company and your desire to reach a mutually beneficial compensation package.
  7. If applicable, express your interest in discussing opportunities for growth and advancement within the company. This demonstrates that you are focused on building a long-term career with the organization.
  8. Be prepared to answer questions about your notice period, availability to start, or any other timing-related considerations

17. Question: Do you have any questions or concerns about our team or company that you'd like to discuss before making a decision?

  • What they are really asking: Are you serious about joining their team, and are your salary expectations in line with their budget?
  • Key points to address: 
  1. Express your genuine interest in the role and the company. Reiterate your enthusiasm for the opportunity and emphasize your eagerness to make a positive contribution to the team.
  2. Seek clarification on any aspects of the role or company culture that are not entirely clear to you. For example, you can ask about the day-to-day responsibilities, team dynamics, or performance expectations.
  3. Inquire about the company's values, mission, and culture. Ask questions related to work-life balance, opportunities for professional growth, and how success is measured within the organization.
  4. Ask about the team you'll be working with, including the size, roles, and any ongoing projects. Understanding the team's dynamics can help you gauge your fit within the group.
  5. Inquire about the current challenges or opportunities the team or company is facing. This shows that you are forward-thinking and interested in contributing to the company's success.
  6. Ask about the company's performance evaluation process and feedback mechanisms. This demonstrates your commitment to continuous improvement and growth

8. Offer Letter and Onboarding:

18. Question: What are your expectations for the onboarding process, and how can we support your transition into the team?

  • What they are really asking: Are you ready to become a part of our organization, and how can they make your transition smooth?
  • Key points to address: Show eagerness to join the team and contribute. Discuss any specific onboarding needs or expectations you may have such as relocation or opportunities like work from home, or hybrid 

By addressing these key points, you can engage in a meaningful discussion that not only helps you gather important information but also showcases your serious interest in the role and your commitment to making an informed decision. Please keep in mind that these questions serve as a base for your interview preparations and questions may vary from company to company but an overall interview process will be somewhat similar to this. I hope you find this informative. I wish you all the best!

We at Alphaa AI are on a mission to tell #1billion #datastories with their unique perspective. We are the community that is creating Citizen Data Scientists, who bring in data first approach to their work, core specialisation, and the organisation.With Saurabh Moody and Preksha Kaparwan you can start your journey as a citizen data scientist.

Need Data Career Counseling. Request Here

Ready to dive into data Science? We can guide you...

Join our Counseling Sessions

Find us on Social for
data nuggets❤️