Diagnose YouTube Usage Decline: Key Metrics and Segmentation
Company: Google
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: hard
Interview Round: Technical Screen
##### Scenario
YouTube observes a sudden decline in daily active users and total watch-time across the platform.
##### Question
How would you systematically diagnose the drop in YouTube usage? Which engagement and funnel metrics would you inspect, and how would you segment users to localize the issue? What further analyses or experiments would you run to confirm root causes?
##### Hints
Frame with acquisition-activation-engagement-retention funnel, segment by device/geo/feature launch, compare cohorts pre- and post-drop, run hold-out or rollback tests to isolate factors.
Quick Answer: This question evaluates a data scientist's competence in product analytics, specifically funnel metric interpretation (acquisition → activation → engagement → retention), user segmentation, monitoring and experimentation design to diagnose sudden declines in platform usage.