ZS Associates Data Scientist Interview Questions + Guide in 2024

ZS Associates is a premier management consulting and technology firm renowned for transforming global healthcare and beyond. At ZS, people are the most valuable asset, working collaboratively to create impactful solutions for patients, caregivers, and consumers worldwide.

The data scientist role at ZS involves advanced machine learning techniques, a strong focus on Natural Language Processing (NLP), and addressing complex business problems with innovative solutions.

This interview guide will help you navigate the different interview stages and prepare you for the commonly asked ZS Associates data scientist interview questions. Let’s get started to prepare you for success!

The interview process usually depends on the role and seniority; however, you can expect the following on a ZS Associates data scientist interview:

Recruiter/Hiring Manager Call Screening

If your CV stands out, you will receive a call from a recruiter or hiring manager. This call typically lasts about 30 minutes and serves to verify key details from your resume, assess your background, and discuss your interest in the role.

Prepare for this conversation by reviewing common behavioral questions and being ready to discuss your previous projects, particularly those related to NLP and machine learning. This is also a good opportunity to ask any questions you might have about the role and the company.

Technical Virtual Interview

Candidates who successfully navigate the screening call will be invited to participate in a virtual technical interview. This stage focuses heavily on machine learning and NLP concepts, as well as practical problem-solving skills.

Expect to tackle a variety of question types, including:

• General ML concepts such as linear regression, logistic regression, decision tree, and random forest
• NLP principles
• Puzzle-solving and conceptual questions, such as explaining machine learning to a seventh grader
• Business case studies and problem statements involving ML algorithms like AdaBoost and backpropagation in LSTM

The technical rounds often include coding tasks, problem-solving scenarios, and detailed discussions about your past projects. Be prepared to showcase your expertise in handling unstructured business problems and delivering pragmatic solutions.

Onsite Interview Rounds

Following the virtual technical interview, you may be invited to onsite interviews. This phase usually involves a series of back-to-back interview rounds with different members of the team, focusing on various aspects of your technical and behavioral capabilities.

During these interviews, you can expect:

• Multiple rounds of behavioral interview questions
• Technical deep-dives into your previous projects, particularly those involving NLP
• Structured and unstructured case studies to evaluate your problem-solving and analytical skills
• Discussions around machine learning algorithms and their applications in business contexts, performance metrics, and regularization techniques

For example, you might be asked about the assumptions of linear regression or to compare different NLP models like seq2seq, word2vec, skip-gram, and GloVe.

Typically, interviews at ZS Associates vary by role and team, but common data scientist interviews follow a fairly standardized process across these question topics.

1. How would you set up an A/B test for button color and position changes?

A team wants to A/B test multiple changes in a sign-up funnel, such as changing a button from red to blue and/or moving it from the top to the bottom of the page. How would you set up this test?

2. How would you forecast Facebook’s revenue for the next year?

You work on the revenue forecasting team at a company like Facebook. An executive asks how much revenue Facebook will make in the coming year. How would you forecast this?

3. How would you investigate if the redesigned email campaign led to an increase in conversion rates?

An E-commerce store’s new marketing manager redesigned the new-user email journey, and conversion rates increased from 40% to 43%. However, the rate was 45% a few months prior. How would you determine if the redesign caused the increase?

4. How would you ensure data quality across different ETL platforms for ZS Associates’ market research?

ZS Associates partnered with a local survey platform for market research in Southern Africa. The data includes pre-quantified and text data in different languages. How would you ensure data quality across ETL pipelines connecting ZS Associates’ data marts with the survey platform’s data warehouses?

5. How would you conduct an experiment to test Uber’s new ETA range feature?

A PM at Uber considers displaying an ETA range (e.g., 3-7 minutes) instead of a direct estimate (e.g., 5 minutes). How would you conduct this experiment and determine if the results are significant?

6. What is the relationship between PCA and K-means clustering?

Explain how Principal Component Analysis (PCA) and K-means clustering can be used together in data analysis. Describe the benefits of using PCA before applying K-means clustering.

7. How would you explain what a p-value is to someone who is not technical?

Explain the concept of a p-value in simple terms to a non-technical person, focusing on its role in determining the significance of results in hypothesis testing.

8. What is the probability that it’s actually raining in Seattle given your friends’ responses?

You called 3 friends in Seattle to ask if it was raining. Each has a ²⁄₃ chance of telling the truth and a ¹⁄₃ chance of lying. All 3 said “Yes.” Calculate the probability that it is actually raining.

9. What is the probability of drawing three cards in increasing order from a shuffled deck of 500 cards?

Imagine a deck of 500 cards numbered from 1 to 500. If you pick three cards one at a time, what is the probability that each subsequent card is larger than the previous one?

10. How would you test if survey responses were filled at random by certain individuals?

You have survey data from multiple-choice questions. Describe a method to test if some individuals filled out the survey randomly rather than truthfully.

11. What is the probability of a biased coin landing heads exactly 5 times out of 6 tosses?

Given a biased coin that lands heads 30% of the time, calculate the probability of getting heads exactly 5 times in 6 tosses.

12. Write a function min_distance to calculate the minimum absolute distance between two elements in an array and return all pairs with that difference.

Given an array of integers, write a function min_distance to calculate the minimum absolute distance between two elements and return all pairs having that absolute difference. Ensure the pairs are returned in ascending order.

13. Write a query to select the top five most expensive projects by budget to employee count ratio, accounting for duplicate rows in the employee_projects table.

We have two tables: projects and employee_projects. Write a query to select the top five most expensive projects by budget to employee count ratio, considering the existence of duplicate rows in the employee_projects table.

14. Write a function to simulate drawing balls from a jar.

Given a list jar with ball colors and a corresponding list n_balls with counts, write a function to simulate drawing a ball from the jar.

15. Design three classes: text_editor, moving_text_editor, and smart_text_editor with specific functionalities.

Design three classes: text_editor, moving_text_editor, and smart_text_editor. Each class should have specific methods for writing, deleting, and performing special operations on text.

16. Write a query to determine the top 5 actions performed during Thanksgiving week and rank them.

Given an events table, write a query to determine the top 5 actions performed during the week of Thanksgiving (11/22/2020 - 11/28/2020) and rank them based on the number of times performed. If two actions were performed equally, they should have the same rank.

You should plan to brush up on any technical skills and try as many practice interview questions and mock interviews as possible. A few tips for acing your ZS Associates interview include:

1. Understand NLP and Machine Learning Concepts: ZS Associates frequently emphasizes NLP in their interviews. Make sure you’re well-versed in ML and NLP algorithms and can discuss them fluidly.
2. Solve Business Case Studies: Practice solving case studies, especially those that pertain to your past projects or the type of work ZS does. Show your ability to approach unstructured problems and deliver structured, data-driven solutions.
3. Review Project Work: Be prepared to discuss your past data science projects in detail, including the challenges you faced, the solutions you implemented, and the impact of your work.

What is the average salary for a Data Scientist at Zs Associates?

What qualities does ZS Associates look for in a candidate for the Data Scientist position?

ZS looks for candidates with strong analytical and problem-solving skills, proficiency in programming languages like Python and Pyspark, and a solid understanding of machine learning, regression, clustering, and classification models. Excellent communication skills, collaboration, and a scaling mindset for project implementation are also crucial. Hands-on analytics experience is highly valued.

How can I best prepare for the Data Scientist interview at ZS Associates?

To best prepare, research the company, focus on fundamental machine learning concepts, and practice coding problems. Detailed case study preparation is also advisable. Utilize resources from Interview Query for practice problems, and review your past projects thoroughly. Develop your problem-solving frameworks and ensure you can explain complex concepts in simpler terms.

The interview process at ZS Associates for the Data Scientist position is multifaceted and rigorous, consisting of technical, HR, and case study rounds.

To get a thorough understanding and to prepare effectively, explore our comprehensive ZS Associates Interview Guide. We have curated a list of interview questions and insights that you might come across. Additionally, you can check out interview guides for other roles to expand your knowledge and readiness.

Check out all our company interview guides for better preparation, and if you have any questions, don’t hesitate to reach out to us.

Good luck with your interview!