Design a video recommendation system
Company: Snapchat
Role: Machine Learning Engineer
Category: ML System Design
Difficulty: medium
Interview Round: Onsite
Quick Answer: This question evaluates competency in building scalable, low-latency personalized recommendation systems, covering candidate generation and ranking, feature store and training-data design, online serving and caching, evaluation and A/B testing, and handling feedback loops, bias, cold-starts, and safety constraints.