Investigate Causes of Increased Driver Wait Time
Scenario
DoorDash observed that driver (Dasher) wait time at restaurants spiked last week versus the prior week.
Task
Walk through how you would debug the increase in Dasher wait time. Specify the metrics, segments, and analyses you would use to find the root cause. If you confirm restaurant understaffing is responsible, propose actions or experiments to address the problem.
Notes and expectations
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Decompose the end-to-end pickup latency funnel and identify which component(s) changed.
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Slice by restaurant, region, time of day, and order mix; distinguish product vs operational causes.
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If understaffing is the driver, outline experiments and operational tests to reduce wait time.
Constraints & Assumptions
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Preserve the scope, facts, inputs, and requested outputs from the prompt above.
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If the prompt leaves a detail unspecified, state a reasonable assumption before relying on it.
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Keep the answer interview-ready: concise enough to present, but concrete enough to implement or evaluate.
Clarifying Questions to Ask
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Clarify the business objective, unit of analysis, time window, exposure definition, and primary metric.
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State assumptions about instrumentation, randomization, sample size, and data quality.
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Separate descriptive analysis from causal claims.
What a Strong Answer Covers
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A metric framework with primary, guardrail, and diagnostic metrics.
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A credible analysis or experiment design with clear assumptions and bias checks.
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SQL/statistical logic for segmentation, variance, confidence, and data validation where relevant.
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An actionable recommendation that explains trade-offs and next steps.
Follow-up Questions
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What sanity checks would you run before trusting the result?
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How would you handle novelty effects, seasonality, or selection bias?
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What decision would you make if metrics disagree?