System designMediumsd-g537

Subject LeaderboardLevel Entry–Mid~30 minCommon in ML systems · Algorithms & data structures interviewsIndustries Software development, Technology, Computer games

Question

Design a small leaderboard for a mobile game with about 100,000 players. When a player finishes a game their score updates, and the app shows the global top 100 plus the player's own rank and a few players around them. Scores change frequently and the leaderboard is read often. Cover how you store scores, how you compute a player's rank, and the main performance trade-off.

What a strong answer looks like

Clarify scale and constraints first. Propose a clean component breakdown, then go deep on the hard parts — data model, bottlenecks, consistency, failure modes — and name the trade-offs you are making.

Learn the concepts

Narrate your design

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Run or narrate your approach, then ask the coach.