Calculate Recent Post Views and Reactions for Social Media
Company: Meta
Role: Data Scientist
Category: Data Manipulation (SQL/Python)
Difficulty: Medium
Interview Round: Technical Screen
info_stream_views
+---------+-----------+--------------+----------+------------+
| post_id | viewer_id | relationship | duration | ds |
+---------+-----------+--------------+----------+------------+
| 101 | 2001 | Friend | 45.7 | 2023-10-01 |
| 102 | 2002 | Unconnected | 67.2 | 2023-10-01 |
| 103 | 2003 | Followee | 12.0 | 2023-10-02 |
| 104 | 2004 | Unconnected | 80.5 | 2023-10-02 |
| 105 | 2005 | Friend | 30.0 | 2023-10-03 |
+---------+-----------+--------------+----------+------------+
post_reactions
+---------+-----------+-------------+------------+
| post_id | viewer_id | post_action | ds |
+---------+-----------+-------------+------------+
| 101 | 2001 | like | 2023-10-01 |
| 101 | 2002 | comment | 2023-10-01 |
| 102 | 2003 | reshare | 2023-10-02 |
| 103 | 2001 | like | 2023-10-02 |
| 104 | 2004 | like | 2023-10-03 |
+---------+-----------+-------------+------------+
##### Scenario
Info stream engagement analytics for a social media platform; need recent metrics about post views and reactions.
##### Question
Write a SQL query to find the number of distinct posts that accumulated at least one view longer than 60 seconds from viewers whose relationship to the author is 'Unconnected' during the last 7 days (relative to today). Write a SQL query to compute the average number of reactions (like, comment, reshare) per post separately for 'Friend' viewers and 'Unconnected' viewers over the last 7 days.
##### Hints
Filter last 7 days, use relationship filter, group/aggregate by post and relationship.
Quick Answer: This question evaluates proficiency in SQL-based data manipulation and analytics, focusing on time-window filtering, grouping and aggregation (distinct counts and averages), and combining view and reaction event tables.