CVS Health Interview Questions

CVS Health Corporation leverages data science to fulfill its mission of improving individual health outcomes. The company’s data science teams utilize sophisticated analytics, machine learning, and AI to extract pivotal insights from massive and diverse datasets, which directly inform operational, customer service, and healthcare delivery strategies.

CVS data scientists work on multi-faceted problems, including enhancing pharmaceutical inventory management, customizing patient care programs, and predicting health outcomes. This has contributed to the company’s clear demand for data scientists, which encompass roughly 30% of CVS’ hiring activities.

SQL questions are a core part of the interview process at CVS Health for data analyst, software engineer, and data scientist roles.

The majority of CVS Health’s SQL questions focus on product metrics. Candidates are expected to demonstrate their ability to measure and analyze relevant product data. Data analytics and A/B Testing are also common topics, where you may be asked to interpret data or extract insights from complex datasets. Some questions you may encounter include:

1. Find all users that are currently “Excited” and have never been “Bored” with a campaign.

You have an ad_impressions table logging users’ reactions to ad campaigns. Write a query to find all users that are currently marked as “Excited” and have never been marked as “Bored” for any campaign.

2. Write a query to get the total amount spent on each item by users who registered for memberships in a certain year.

You work at Costco and have a users table with registration info and a purchases table with each user’s purchase history. Find the total amount spent on each item by users who registered in 2022.

3. Determine the number of rows from different types of join operations.

You are working at Allstate with an ads table that ranks online ads by popularity. Create a subquery or common table expression named top_ads for the Top 3 ads, returning the number of rows resulting from four join operations with this subquery.

To continue practicing SQL, try the SQL learning path and the full list of SQL questions and solutions in our interview questions database.

Coding questions are another integral part of the CVS hiring process, especially for data engineer, data scientist, and software engineer interviews.

The majority of CVS Health’s coding questions revolve around coding fundamentals and problem-solving. Candidates are assessed on their ability to write clean, efficient code and solve complex problems using optimal algorithms and data structures.

4. Create a function to determine if two strings are anagrams of one another.

Write a function to return True if the strings are anagrams of each other and False if they’re not. Note: a word is not an anagram of itself.

5. Write a function to remove stop words from a string.

Given a list of stop words, write a function stopwords_stripped that takes a string and returns a string stripped of the stop words with all lowercase characters.

6. Design a function to determine if a string is a palindrome.

Given a string, write a function that returns True if a string is a palindrome and False if it is not. Note: a palindrome is a word/string that is read the same way forward as it is backward (ex: madam).

To practice coding interview questions, check out the Python learning path or the full list of Algorithms questions in our database.

Case study questions are designed to assess a candidate’s ability to work through real-world scenarios. They appear in around 40% of CVS Health interviews.

The bulk of CVS Health’s case study questions concentrates on business analysis and data science concepts, focusing on interpreting complex data and translating insights into strategic decisions. These questions are particularly common for roles such as data scientists, business analysts, and data engineers.

7. How would you interpret the significance of a single variant in an A/B test?

In an A/B test run by your manager, 20 different variants are tested and one is reported as significant. Consider whether these results raise any questions or concerns.

8. How would you determine the true impact of a redesigned email campaign on conversion rates?

You work for an e-commerce store. A redesigned new-user email journey appears to boost customer conversion rates, but a previous drop in these rates creates uncertainty. Determine whether the email campaign or other factors actually led to the increase in conversions.

9. What considerations should be made when testing hundreds of hypotheses using t-tests?

While performing hundreds of t-tests to examine various hypotheses, consider the factors that could impact the interpretation and validity of your results. What can be done to correct for these factors?

Find additional case study resources in our product metrics learning path and the data analytics learning path.

Statistics and probability questions are a significant part of CVS interviews for multiple data roles. A strong grasp on statistical theory and application is important for understanding the underlying concepts behind AB testing and other fundamental topics.

10. Determine the fairness of a coin based on the outcome of 10 flips.

You flip a coin 10 times, resulting in 8 tails and 2 heads. Is this coin biased?

11. How many students actually won in a coin-tossing game based on their responses?

100 students play a coin-tossing game where heads is a win and tails requires another flip. If heads appear on the second flip, students lie about winning. Determine the actual number of winners if 30 students claim they won.

12. What are the drawbacks of only using R-Squared to assess how well a model fits a data set?

You’re looking to establish a relationship between two variables and need to analyze how well a model fits a given set of data. Assess the potential downsides of relying solely on $R^2$ for this task.

To prepare for probability and statistics interview questions, check out the comprehensive probability learning path. It covers basic to advanced probability concepts, including multivariate distributions and sampling theorems.

While assessed less frequently compared to other topics, machine learning is still an important part of interviewing for data science positions at CVS. The company places a significant emphasis on candidates’ understanding of machine learning, as it plays a major role in operations and service delivery.

13. Explain how a random forest generates the forest and why it would be used instead of other algorithms.

Compare random forests to similar algorithms, like logistic regression.

14. When would you use bagging versus boosting algorithms?

Define both machine learning algorithms and provide an example illustrating the tradeoffs between the two.

15. What assumptions are made in linear regression?

Explain the assumptions in the linear regression model and consider what occurs when they are violated.

To prepare for machine learning interview questions, we recommend using the machine learning course.

Practice for the CVS Health interview with these recently asked interview questions.