The Schema That Could Not Answer Back
A hard 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
- hard
- Seniority
- L5
Interview Prompt
A personal styling service tracks shipments in a single wide denormalized table with one row per shipment, repeating item attributes across numbered columns. The business wants to add return reasons, calculate client lifetime value, and attribute revenue by brand. The current table cannot answer these questions without significant ETL changes. Redesign it.
Summary
Forty columns in. Zero useful answers out.
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