# Sample Data Science Interview questions from Facebook:

We analyzed the Interview experiences of data scientists at Facebook posted on Glassdoor and posted common interview questions on our Sample Interview Questions site.

The questions fall in one of the four themes:

- SQL Questions
- Probability and Statistics 101 questions
- Product-Intuition questions
- Machine learning & engineering questions

Also, the questions that you get if you are interviewing will depend on which type of data scientist that you are applying for:

- Data Science [Software engineering]: Questions are common coding questions and machine learning focused
- Data Science [Analytics]: Questions are SQL and Product Intuition focused
- Data Science [Research]: Questions are Statistics and Machine learning engineering focused

Also, it’s common to receive a take-home challenge. So check out Five tips here: Five tips for Take-home data science challenge

With that background, here are common interview questions for data science roles at Facebook:

- If we were testing product X, what metrics would you look at to determine if it is a success?
- [SQL] Write an SQL query that makes recommendations using the pages that your friends liked. Assume you have two tables: a two-column table of users and their friends, and a two-column table of users and the pages they liked. It should not recommend pages you already like.
- [Probability] There are 50 cards of 5 different colors. It comprises of 10 Red cards, 10 blue cards, 10 orange cards, 10 green cards and 10 yellow cards. Each color will have the cards numbered between 1 to10. You pick 2 cards at random. What is the probability that they are not of same color and not of same number.
- [SQL] Given two tables Friend_request (requester_id, sent_to_id , time) Request_accepted (acceptor_id, requestor_id, time) Find the overall acceptance rate of requests.
- [Probability] There’s a game where you are given two fair six-sided dice and asked to roll. If the sum of the values on the dice equals seven, then you win $21. However, you must pay $5 to play each time you roll both dice. Do you play this game? And in follow-up: What is the probability of making money from this game?
- [SQL] The success ratio of sending messages given sent and receive table
- What experiment would you run to implement new features on Facebook?
- [SQL] How to keep a nightly count of songs listened by users based on a real-time transaction table. See Description:
- Why Facebook? [Interview answer template can be found here: Why do you want to data science at our company?]

Hope that helps! And if you want to practice data science interviews, sign up on MockInterview.co — it’s FREE for a limited time so it’s a great time to sign up!