Leaderboards / Top-K

Maintain scores in an ordered structure#

Repeatedly sorting every player for every top 100 request becomes expensive. An ordered (score, user) structure supports score updates, Top-K ranges, and a user's rank. Redis sorted sets are one implementation, not the architecture itself.

Ties need deterministic policy. Sharded global Top-K can merge each shard's candidates, while user rank across shards is harder. Approximate heavy-hitter structures belong only when exactness is not required.