DoorDash·Data Scientist·Technical Phone Screen
- DoorDash is launching in a new city. Define success metrics and guardrails for three phases: pre-launch readiness, soft launch, and full ramp. For each phase, specify core metrics with precise definitions, distinguish leading indicators from outcome metrics, and set guardrail thresholds that would trigger a rollback or pause.
- Design a geo-based A/B or staggered rollout to estimate the causal impact of the city launch on orders and ETAs. Address seasonality, matched-control zone selection, spillover effects across adjacent zones, novelty effects, and minimum detectable effect assumptions. What decision rules would you present to leadership after two weeks?
“The three-phase structure sounds clean until you're actually in it and realize pre-launch has almost no live data to work with.”