Rank Newly Launched Ads Under Cold Start
Company: Pinterest
Role: Machine Learning Engineer
Category: ML System Design
Difficulty: medium
Interview Round: Onsite
Overview: Design a cold-start ranker for ads launched within the last seven days. Combine creative, campaign, advertiser, context, and uncertainty signals with safe exploration, delayed-label evaluation, calibrated serving, marketplace guardrails, and a smooth handoff to the mature model.