Demo case file · System design
Logistics company
Data Engineer
This is a demo case file: a realistic example written from commonly known interview formats, not a real candidate's interview experience.
Questions asked
- Design a pipeline that ingests GPS pings from 20,000 delivery vans every 10 seconds and powers both a live map and daily analytics.
- How do you handle late-arriving and duplicate events?
- How would you model the warehouse tables to report "on-time delivery rate by region"?
What to expect
They wanted me to size the traffic first (about 2,000 events per second) and explain why a streaming path and a batch path had different needs. Idempotent writes and event-time versus processing-time came up in detail. Ended with a quick star-schema sketch.
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