Design a Played-By Summary System
Company: Roblox
Role: Software Engineer
Category: System Design
Difficulty: hard
Interview Round: Technical Screen
Overview: This system design question evaluates a candidate's ability to decompose a personalized social-proof feature into distinct distributed systems problems: maintaining an idempotent unique-player count at high write throughput and efficiently computing a per-viewer friend intersection at read time. It tests mastery of event-driven architectures, deduplication strategies, hotspot mitigation, caching hierarchies, and consistency trade-offs commonly assessed in senior software engineering interviews.