The Firehose and the Ledger
A hard Pipeline Design 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
- Pipeline Design
- Difficulty
- hard
- Seniority
- senior
Interview Prompt
When a partner comes back from an outage and replays its backlog, our daily ledger double-counts and the live partner view stalls behind it. Design the pipeline that takes about 2 billion payment events a day from a few hundred partner APIs, some pushing webhooks and some polled on a schedule, and serves both operations and finance.
How This Interview Works
- Read the vague prompt (just like a real interview)
- Ask clarifying questions to the AI interviewer
- Draw your pipeline on the design canvas: sources, transforms, storage and checks
- Answer the interviewer's follow-up questions, then get a hire or no-hire decision