Design Instagram (Feed, Photos, and Friend Recommendations)

Company: Anthropic

Role: Software Engineer

Category: System Design

Difficulty: medium

Interview Round: Onsite

Quick Answer: This question evaluates a candidate's ability to design a large-scale, read-heavy social media backend, covering data modeling for follow graphs, media storage, and feed generation. It tests system design skills such as choosing fan-out strategies for feed delivery, handling highly skewed follower distributions, and reasoning about latency and availability trade-offs at scale.