Design weapon-selling ad detection from posts
Company: Meta
Role: Machine Learning Engineer
Category: ML System Design
Difficulty: medium
Interview Round: Onsite
Quick Answer: This question evaluates a candidate's ability to design a production-scale multimodal ML system for detecting weapon-selling ads, testing competencies in policy definition, data and labeling strategy, multimodal feature/model design, robustness to evasion, latency and precision/recall trade-offs, human-in-the-loop workflows, monitoring, and privacy-aware deployment. It is commonly asked in the ML system design domain to assess architectural thinking for safety-critical content moderation and operational MLOps, requiring both conceptual understanding of policy and trade-offs and practical application for deployment, evaluation, and iteration.