Every Line Remembered
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 sales reports cannot be trusted: when a customer moves, last year's sales by city follow them to the new address, and when a retired product relaunches under its old identifier it inherits the retired item's sales. Redesign the retail chain's transactional orders, customers, products, stores and employees as a dimensional warehouse where every line item of an order is its own sales record, still traceable to its order and tied to the customer, product, store, employee and date of the sale. Each sale must keep the address its customer had on the order date while we can still see where every customer lives now, and digital storefronts with no physical location must report as stores alongside the physical ones.
Summary
Customers move, products relaunch, and some stores have no address. Reshape the tables so nothing gets forgotten.
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