window-function Interview Questions

Data aggregation and relational database manipulation are critical skills for data professionals, frequently highlighted in evaluations like this reported Notion interview question. You will need to write an efficient query to identify the most active category of user actions and subsequently determine the predominant subscription tier linked to those specific interactions. The challenge evaluates your capability to join multiple relational tables and handle complex many-to-one relationships. Unlock the full problem breakdown and expert SQL solution with a subscription.

This relational database screening evaluation was featured in a Notion engineering interview, focusing on complex querying over multiple business tables. You will tackle practical data retrieval scenarios involving advanced joins, subqueries, and window functions to extract precise metrics. The exercise measures your ability to write performant queries while correctly managing nulls and row aggregation. Get the complete set of prompts and verified SQL solutions by subscribing today.

This Zoox SQL query problem requires you to analyze transactional data to identify top-performing vendors. You need to aggregate transaction amounts for each vendor within specific geographical regions (state and city) over the past two years, calculating a net amount that accounts for both purchases and refunds. The final output should list the top three vendors for each unique state-city combination, ranked by their net amount. This question specifically tests your proficiency with SQL window functions for ranking and data aggregation. The full problem statement and a model solution are available with a subscription.