Facebook Data Scientist | November 2020
Position: Data Scientist
How was the interview process? What was it like?
Product Based Questions
What technical questions were asked?
What was one of your solutions?
WITH first_time AS (
SELECT caller_id, MIN(date) AS date_used
GROUP BY caller_id
SELECT users.caller_id, first_time.date_used AS first_time_used, users.date AS usage_date, users.date - first_time.date_used AS days_between, DATEDIFF('day', users.date, first_time.date_used) AS days_between
LEFT JOIN users
ON first_time.caller_id = users.caller_id
AND first_time.date_used < users.date
WHERE first_time.date_used = '2019-03-01' AND days_between = X