Validate in-post restaurant recommendations via experiment
Company: Meta
Role: Data Scientist
Category: Analytics & Experimentation
Difficulty: hard
Interview Round: Onsite
Your product adds in-post restaurant recommendations. Design the evaluation:
1) Define goals and success metrics at viewer and creator levels (e.g., CTR on recommendations, saves, downstream bookings/orders within 24h/7d, session time, creator engagement) and guardrails (dwell quality, hide/mute rates).
2) Experiment design: unit of randomization (viewer, post, or session), handling feed/network interference, ramp plan, and holdout design for creators.
3) MDE and power: given baseline recommendation CTR = 8% and MDE = +0.4 pp, outline sample size and test horizon; address multiple comparisons across locales/categories.
4) Cold-start and bias: ensure fair exposure for new restaurants and new users; handle popularity bias and position bias (use randomization or IPS).
5) Offline vs online evaluation: offline ranking metrics (NDCG@K, MAP) on logged data, counterfactual reweighting, and exploration via bandits while preserving unbiased treatment effect estimates. 6) Risk checks: measures to prevent irrelevant or unsafe suggestions; rollback criteria and post-launch monitoring for long-term retention effects.
Quick Answer: This question evaluates a data scientist's competency in experimental design for recommendation systems, including defining viewer- and creator-level metrics and guardrails, statistical power and MDE estimation, fairness and bias mitigation, offline versus online evaluation, and risk/rollback planning within the Analytics & Experimentation domain.