Every Line Counts
A medium Data Modeling 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
- Data Modeling
- Difficulty
- medium
- Seniority
- L5
Interview Prompt
Design the star schema that holds every item scanned at the registers of our 500 stores, one row per receipt line, so the merchandising analytics team can slice sales by store, product, date and the promotion applied, rolling up to region, department and fiscal period. A promotion covers many products and a product can sit in several running promotions at once, each pairing with its own discount, but the register applies at most one promotion to any given line.
Summary
Every beep at the register. Coupons, returns, all of it.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Draw your data model on the schema canvas: tables, keys and relationships
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision