The Table That Lies
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
Our operational database has a single wide table with one row per stylist-client session. It contains client attributes, stylist attributes, session metadata, and item-level details all flattened together. Analysts struggle to write correct queries against it and frequently produce wrong aggregations. Design a normalized data model to replace it.
Summary
Every query comes out wrong. The data is all there.
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