Diagnose post-release conversion regression rigorously
Company: Apple
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: medium
Interview Round: Technical Screen
Overview: Design an analysis to decide whether a full rollout of version 7.3 caused signup conversion to fall from 5.4% to 4.9%, then recommend what to do next. With no group left on the old version, the comparison has to be created, such as a geo holdout, while ruling out tracking, bot and campaign changes.