Shared Category Purchasers

A medium SQL mock interview question on DataDriven, with an AI interviewer who asks follow-up questions and a hire or no-hire decision at the end.

Domain

SQL

Difficulty

medium

Seniority

L4

Interview Prompt

The recommendations team is building a collaborative filtering feature and wants co-purchasers who shop the same aisle. For each product category, find every pair of users who both bought in it and count the ways one user's purchases there combine with the other's.

Summary

They bought different things from the same aisle.

How This Interview Works

1. Read the vague prompt (just like a real interview)
2. Ask clarifying questions to the AI interviewer
3. Write and run your SQL against a real database
4. Answer the interviewer's follow-up questions, then get a hire or no-hire decision