Facebook SQL Interview Questions

Data scientist and data analyst roles at Facebook are amongst the most coveted positions in the realm of tech. Careers in this field are extremely rewarding, both in compensation and exposure, encouraging many engineers to apply. Data engineers enjoy the highest non-executive starting compensation packages that can range anywhere between $150k-$190k, according to Glassdoor.

Facebook actively hires for data analyst roles that fundamentally involve leveraging SQL to manage data in relational databases. Thus, to succeed at data analyst interviews, one must be adept with SQL, object-oriented programming languages, and database management.

Data analyst interviews at Facebook are slightly different from regular technical interviews for software developers that predominantly focus on coding and design.

In this article, we’ll look at some common Facebook SQL coding interview questions to give you a fair idea of what to expect from data analyst interviews at Facebook.

Here is what this article will cover:

• The Data Analyst Interview Process at Facebook
• Facebook SQL Interview Questions and Answers
• How to Prepare for Your Next SQL Interview

The Data Analyst Interview Process at Facebook

If you’re applying for a data analyst role at Facebook, here is how the interview process will pan out:

Initial Phone Screen

The first phone screen is usually with a recruiter, who evaluates your profile and discusses your experience and skills to understand if you’re the right fit for the role. The recruiter will also try to understand if you have a genuine interest in the company and assess your communication skills.

Note that data analyst positions require a different skill-set that doesn’t particularly pertain to algorithms and systems design. Questions lean more toward relational databases and solving problems using SQL.

Technical Phone Screen

The next phone screen will be with a hiring manager or technical lead from Facebook’s data science department. During this 30-45-minute call, the interviewer will evaluate your core technical SQL and data analysis skills. In this round, given a data set and 1-2 questions on the data set, you’ll have to employ program code to solve them. Note that the interviewer won’t ask you to execute your code, so make sure you’re adept with SQL syntax to avert syntax errors during your interview.

Onsite Interviews

The onsite interviews involve a series of interviews to evaluate your core data analysis skills and other aspects such as your programming and behavioral skills.  

The onsite interviews typically span 2-3 hours. Here’s what to expect at Facebook’s data analyst onsite interview:

• An SQL technical question: Interviewers will ask you a question or two on leveraging a data set using SQL queries.
• A product interpretation question: They’ll give you some data on a specific product trend, and ask you to measure product performance and how to best improve its performance by using A/B testing and other methods.
• A quantitative analysis question: They’ll expect you to solve a statistics-oriented question where interviewers will gauge your understanding of statistical data analysis.
• An applied data question: They’ll ask you to leverage data and use it to develop innovative strategies for a given product/service.

Typically, the first two rounds of onsite interviews will be more technical, and the last two will be more behavioral. During these rounds, they’ll ask you more situational questions to assess if you’ll be a good fit in terms of personality, work ethic, and attitude.

Additional Reading: Behavioral Interview Questions for Software Developers

Facebook SQL Interview Questions and Answers

Here are a couple of sample SQL interview questions and answers to help you with your interview preparation:

Question 1: What is the difference between Truncate and Drop?

Drop and Truncate are both:

• Data Definition Language (DDL) commands
• Used for data deletion
• Commands that can’t be rolled back after usage
• Do not contain the Where clause

Following are the key differences that you can talk about while answering this question:

Question 2: What is the difference between Partition and INDEX?

Some differences between Partition and Index in SQL are:

Below are some more sample SQL coding questions to help you prepare for your Facebook SQL interview:

1. Given a dataset of users, both existing and new, calculate the share of new and existing users and return the output as a ratio. New users are those who began using services in the current month. Existing users are those who started using services in the current month and used services in any previous month.
2. If you have two ETL jobs that feed into a production table every day, do you think any problems could emerge in this setup?
3. Given a table with user_ids and dates on which users visited a specific platform, find out the top 100 visitors using SQL until yesterday.
4. You’re given two tables - one which reflects the number of messages sent by Facebook and another that reflects the number of users who responded to the message. Write an SQL query to calculate the confirmation percentage in this case.
5. You’re given a table with complaint tickets covering different types of complaints. Write an SQL query to find the number of tickets under each type and the number of processed tickets under each category.
6. You’re given a table with a million rows. Tell us how you’d add a column from the original data source without impacting the user experience?
7. Say you have a table that represents the salaries of employees in a company. The table represents the annual salaries of employees from different departments, with bonuses and variable compensation packages. Write an SQL query to derive the monthly salary of a particular employee and whether or not the employee must receive their variable compensation for the given month.
8. Explain the process of designing a database for a Fastfood restaurant.
9. Create a Schema table to represent the client click rate for a given digital campaign.
10. You’re given a dataset schema that contains information about different buyers on an e-commerce site. Write an SQL query to compute the total sales of a given product on a given day.
11. A bakery sells X items in the first three hours of a given day and X+n number of items during the last three hours of the day. Write an SQL query to determine the total value of item “v” sales during the last three hours of the day.

Related Reading:
Amazon SQL Interview Questions
Oracle SQL Interview Questions

How to Prepare for Your Next Facebook SQL Interview?

Here are three key tips to start your Facebook SQL interview preparation:

• Get good with your programming language: You’ll have to be good with an Object-Oriented Programming Language, preferably Python or Java. Make sure you brush up on concepts around your language, especially those we use to process data and information.
• Practice a variety of SQL coding interview questions: Practice as many problems that employ a wide range of SQL queries as possible. Work on different datasets and implement queries for different results.
• Practice SQL mock interviews: With mock interviews, you can understand which areas need improvement and which areas are your strong suit. Practicing mocks with professionals who’re privy to interview processes at big companies is a big plus point, as they’ll tell you exactly what recruiters are looking for in candidates. Interview Kickstart helps you practice mock interviews with technical leads and hiring managers from FAANG companies.

Gear Up for Your Next Facebook Interview

Whether you’re a Coding Engineer gunning for Software Developer or Software Engineer roles, a Tech Lead, or you’re targeting management positions at top companies, IK offers courses specifically designed for your needs to help you with your technical interview preparation!

If your big interview is just around the corner, register for Interview Kickstart’s technical interview webinar to find out how we can help you crack tough technical interviews at the biggest companies.

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