Design a Real-Time Gaming Leaderboard

A Real-Time Gaming Leaderboard tracks, sorts, and displays player scores and rankings across millions of active gamers globally with instant sub-millisecond updates.

Functional Requirements

1. Update Player Score: Update a player's score after completing a game or match: updateScore(userId, score).
2. Retrieve Top-N Leaderboard: Fetch the global top 10, 50, or 100 players ordered by score: getTopPlayers(N).
3. Retrieve Player Exact Rank: Fetch an individual player's current numerical rank (e.g., "You are ranked #1,402 of 10M players"): getPlayerRank(userId).
4. Surrounding Rank (Friends / Vicinity): Fetch a user's relative ranking window (e.g., the 5 players immediately above and below them).
5. Seasonal Partitions & Resets: Support monthly/seasonal leaderboard resets with historical archiving.

Non-Functional Requirements

• Sub-Millisecond Read & Write Latency: Score updates and rank queries must return in < 1 ms (p99).
• High Concurrency Throughput: Handle > 50,000 score updates/second during peak multiplayer gaming hours.
• Strict Real-Time Accuracy: When a player wins points, their updated rank must reflect on global scoreboards immediately.