drlappies / catch-game-service

catch-game-service

• It's the backend for the game catch-game-web that handles and stores the leaderboard.
• It's a simple API server with 2 apis: Add record to leaderboard and get top 100 players from the leaderboard.

Getting started

• Run docker-compose up -d to run Redis locally on port 6379
• Run yarn start:dev run the project locally on port 8080

Techonologies

• Node.js (API server)
• Redis (Leaderboard persistance)

Design

• Node.js because I use node.js most of the time.
• Redis sorted set is good for leaderboard. And it's efficient to get/set values using it. Most of the operations on ZSET are O(log(n)) and it supports sorting (ZREVRANGE/ZRANK) of the leaderboard out of the box.

Tie-breaker

• Players can sometimes have same score, so players who set the score record earlier would be prioitised on the leaderboard. e.g player A scored 100 on 2024-Jan-1 should have a higher ranking than player B who scored same score on 2024-Jan-2.