Optimize IG Shopping ranking with multiple objectives
Company: Meta
Role: Data Scientist
Category: Machine Learning
Difficulty: hard
Interview Round: Onsite
Instagram Shopping home feed must optimize buyer GMV, buyer satisfaction, and seller fairness. Propose a multi-objective ranking framework that: (a) predicts purchase probability, return risk, and post-purchase satisfaction, (b) enforces seller-level minimum exposure constraints and cold-start seller exploration, (c) is robust to fraudulent sellers and fake engagement, and (d) supports on-device prefetching with a 20 ms budget. Describe your model family (e.g., multi-task, calibrated scores), objective aggregation (e.g., constrained optimization or learned utility), and training data sampling to counter selection bias from historical rankings. How do you monitor fairness and fraud drift post-launch and throttle supply during spikes (e.g., flash sales)?
Quick Answer: This question evaluates multi-objective ranking and recommender-system competencies, including predictive modeling and calibration, constrained objective aggregation, seller-level fairness constraints, fraud robustness, selection-bias-aware training, and latency-aware on-device deployment.