System designMediumsd-g014

Subject Real time systemsLevel Mid–Senior~35 minCommon in Distributed systems · Algorithms & data structures interviewsIndustries Technology, Computer games

Question

Design a real-time global leaderboard for a competitive game with 80M monthly players: scores update constantly during matches, players want their exact rank and the top-100 to refresh within ~1s, and you also need 'players near my rank' and weekly/seasonal resets. Walk through the data structures and how you keep rank queries fast at this scale.

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.