11. Real Time Leaderboard


Design a real time leaderboard for a popular competitive game to track the top players that season

Functional Requirements
  • Each time a player scores in a game we should add a point to their total score
  • Leaderboards are refreshed each quarter year
  • 25 users should be displayed on the leaderoard
Nonfunctional Requirements
  • The leaderboard needs to be updated within 100 milliseconds of a change
  • 99.9% availability
  • Tie goes to whoever was at that position first
  • We do not need to support search
Estimated Usage
  • On average each user earns 30 points per day
  • 3 million daily active players
  • 8 million daily active viewers

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