The Shape of a Run
A medium Data Modeling mock interview question on DataDriven. Practice with AI-powered feedback, real code execution, and a hire/no-hire decision.
- Domain
- Data Modeling
- Difficulty
- medium
- Seniority
- L5
Interview Prompt
Every machine in our fleet emits one log line when a process starts and a separate line when it stops, and each line records the machine, a process id the machine assigns locally, which kind of event it was, and a timestamp in float seconds. The warehouse has to keep every line exactly as it arrived so analysts can reconcile a start with its matching stop themselves, computing the average elapsed time per process, drawing per-machine timelines of every process in order, and flagging starts that never got a stop. Design the data model behind this log and describe how the daily files load in through an ETL.
Summary
Two log lines bracket every process. Pair them and the fleet's rhythm appears.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Write your data modeling solution with real code execution
- Get instant feedback and a hire/no-hire decision