I applied through an employee referral.

I interviewed at Facebook United States in August 2020.

Interview

Data Engineer Phone Interview. Most of them explained the process earlier. The interview lasted for 1 hour.

I was able to answer 2.5 SQL and 3 Python questions. Most of the time was spent understanding the schema and the data for sales and promotions. The answers needed to exactly match the expected values.

I got stuck on the second question and spent most of my time on it. Time is a constraint. Understand the data for all tables and start writing queries that will help you complete them faster.

SQL questions on promotions, sales schema.

1. Find the top 5 best-selling products that had promotions.
2. What percentage of sales occurred on the first and last day of the promotion?

Python:

1. Given a list like [1, None, 1, 2, None], return [1, 1, 1, 2, 2]. Ensure you handle input [None] which means None objects.
2. Find all occurrences of 's' in "mississippi".
3. Complete a function that returns a list containing all the mismatched words (case sensitive) between two given input strings.
   • For example:
     • String 1: "Firstly this is the first string"
     • String 2: "Next is the second string"
   • Output: ['Firstly', 'this', 'first', 'Next', 'second']