Roku Data Scientist Interview Questions + Guide in 2024

Roku is at the forefront of TV streaming technology and the #1 streaming platform in the US, redefining how the world consumes content. The Senior Data Scientist role at Roku blends technical expertise, data analysis, and collaboration with cross-functional teams to drive impactful business insights and decision-making. In this role, you’ll work with Big Data technologies, statistical methods, and visualization tools to deliver actionable recommendations that shape the company’s strategy.

Are you ready to take on complex analytical challenges and contribute to the future of TV streaming in a dynamic and fast-paced environment? This guide will walk you through the interview process, providing an overview of what to expect. You’ll gain insight into the type of Roku data scientist interview questions typically asked and tips on standing out, equipping you to confidently approach the interview and significantly improve your chances of landing the role. Let’s get started!

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

Recruiter/Hiring Manager Call Screening

If your CV happens to be among the shortlisted few, a recruiter from the Roku Talent Acquisition Team will make contact and verify key details like your experiences and skill level. Behavioral questions may also be a part of the screening process.

In some cases, the Roku Senior Data Scientist hiring manager stays present during the screening round to answer your queries about the role and the company itself. They may also indulge in surface-level technical and behavioral discussions.

The whole recruiter call should take about 30 minutes.

Technical Virtual Interview

Successfully navigating the recruiter round will present you with an invitation for the technical screening round. Technical screening for the Roku Senior Data Scientist role usually is conducted through virtual means including video conference and screen sharing. Questions in this 1-hour long interview stage may revolve around SQL exercises, statistical methods (such as p-value, logistic regression, and OLS requirements), and correlation between data.

In some cases, a business case may also be presented during this stage. Be prepared to answer constructively even if the business case appears vague. Additionally, proficiency in hypothesis testing, probability distributions, and machine learning fundamentals may be assessed.

Onsite Interview Rounds

Followed by a second recruiter call outlining the next stage, you’ll be invited to attend the onsite interview loop. Multiple interview rounds will be conducted during your day at the Roku office. Your technical prowess, including programming and ML modeling capabilities, will be evaluated against the finalized candidates throughout these interviews.

If you were assigned take-home exercises, a presentation round may also await you during the onsite interview for the Senior Data Scientist role at Roku.

The onsite interviews will also focus on your ability to develop data visualizations using platforms like Tableau or Looker, design and evaluate A/B experiments, and communicate your insights effectively with senior stakeholders.

By accurately preparing for these stages, you can position yourself as a strong candidate for a Senior Data Scientist role at Roku Inc. Good luck!

Practice for the Roku data scientist interview with these recently asked interview questions.

Roku Inc. Data Scientist Coding and Algorithms Interview Questions

Coding and algorithms questions arise in 85% of Roku Inc. job interviews. They are most common in business intelligence (97%), software engineer (97%), and data analyst (43%) interviews.

1. Write a query to get the average order value by gender.

Given three tables representing customer transactions and customer attributes, write a query to get the average order value by gender. Round the answer to two decimal places.

2. Write a function missing_number to find the missing number in an array.

You have an array of integers, nums of length n spanning 0 to n with one missing. Write a function missing_number that returns the missing number in the array. Complexity of (O(n)) required.

3. Find the index where the sum of the left half equals the right half in a list.

Given a list of integers, find the index at which the sum of the left half of the list is equal to the right half. If there is no such index, return -1.

4. Write a function sorting to sort a list of strings in ascending order from scratch.

Given a list of strings, write a function, sorting to sort the list in ascending alphabetical order without using the built-in sorted function. Return the new sorted list.

5. Write a query to extract the earliest date each user played their third unique song.

Given a table of song_plays and a table of users, write a query to extract the earliest date each user played their third unique song. If a user has listened to less than three unique songs, display their name with a NULL date and song name.

To practice Algorithms interview questions, consider using the Python learning path or the full list of Algorithms questions in our database.

Roku Inc. Data Scientist Analytics and Experiments Interview Questions

Analytics and experiments questions arise in 38% of Roku Inc. job interviews. They are most frequently asked during data analyst (97%) and data scientist (30%) interviews.

6. How would you build a model to predict which merchants DoorDash should acquire in a new market?

As a data scientist at DoorDash, describe the steps and features you would use to build a predictive model for identifying potential merchants for acquisition when entering a new market.

7. How would you determine customer service quality through the chat box for small businesses on Facebook Marketplace?

Your team at Facebook focuses on helping small businesses increase sales through the Marketplace app. Explain how you would assess the quality of customer service interactions via the chat box for these businesses.

8. What business health metrics would you track on a dashboard for an e-commerce D2C sock business?

As the person in charge of an e-commerce D2C business selling socks, list and explain the key business health metrics you would monitor on a company dashboard.

9. Write a query to determine if user interactions (likes, comments) lead to higher purchasing volumes.

Given three tables (users, transactions, and events), write a SQL query to analyze whether users who interact on the website (through likes and comments) have a higher purchasing volume compared to those who do not interact.

To prepare for analytics and experiments, consider using the product metrics learning path and the data analytics learning path.

Roku Inc. Data Scientist Machine Learning Interview Questions

Machine learning questions come up in 9% of Roku Inc. job interviews. They are most frequently asked during data scientist (22%) interviews.

10. How does random forest generate the forest and why use it over logistic regression?

Explain the process of generating a forest in a random forest algorithm and discuss the advantages of using random forest over logistic regression.

11. How do we deal with missing square footage data to construct a housing price model?

You have 100K sold listings over the past three years for Seattle, but 20% are missing square footage data. Describe methods to handle this missing data to build an accurate housing price prediction model.

12. How do you detect and handle correlation between variables in linear regression?

Describe methods to detect and manage correlation between variables in a linear regression model. Explain the consequences of ignoring such correlations.

13. How would you design a model to detect potential bombs at a border crossing?

Outline the design of a model to detect potential bombs at a border crossing, including the selection of inputs and outputs, accuracy measurement, and testing procedures.

To get ready for machine learning interview questions, we recommend taking the machine learning course.

Roku Inc. Data Scientist Statistics and Probability Interview Questions

Statistics and probability questions appear in 6% of Roku Inc. job interviews. There is no specific data on the positions for which these questions tend to come up.

14. How many more samples are needed to decrease the margin of error from 3 to 0.3?

Given a sample size (n) with a margin of error of 3, calculate the additional samples required to reduce the margin of error to 0.3.

15. What is the mean and variance of the distribution of (2X - Y)?

Given (X) and (Y) are independent random variables with normal distributions (X \sim \mathcal{N}(3, 4)) and (Y \sim \mathcal{N}(1, 4)), determine the mean and variance of (2X - Y).

16. How do you calculate the sample size and power for an AB test?

For an AB test with a test group and a control group: 1. How do you calculate the necessary sample size for accurate measurement? 2. If the sample size is sufficient, should the power increase or decrease to measure very small differences?

To prepare for statistics and probability interview questions, consider using the A/B testing and statistics learning path and the comprehensive probability learning path. These resources cover essential concepts and advanced topics.

Here are some tips on how you can ace your Roku data scientist interview:

1. Master SQL and Big Data Frameworks: The technical screening will heavily focus on SQL exercises and handling Big Data. Revisit your SQL skills and familiarize yourself with data manipulation on large datasets.

2. Be Ready for Business Cases: The interview may include ambiguous business cases to assess your problem-solving approach and business intuition. Practice structured thinking and clear communication of your thought process.

3. Emphasize Your Communicative and Collaborative Skills: Roku places high importance on the ability to collaborate with senior stakeholders and communicate complex analyses clearly. Prepare to discuss your past experiences involving multidimensional teamwork and presentation.

The Data Scientist role at Roku Inc. offers a unique opportunity to tackle technical challenges while driving business impact in the fast-evolving world of TV streaming. This position allows you to combine technical expertise with strategic insights, enhancing the viewer experience for millions of users.

If you want more insights about the company, check out our main Roku Interview Guide, where we have covered many interview questions that could be asked. Additionally, explore our interview guides for other roles such as software engineer and data analyst to learn more about Roku’s interview process for different positions.

Good luck with your interview!