Matchmaking queues need three things from their core data structure: range-count queries as the skill window widens, global rank lookups for leaderboards, and constant add/remove updates. The usual default is a skip-list-backed sorted set, the kind Redis ships and OpenMatch used, but benchmarked...
Source: [HackerNoon](https://hackernoon.com/why-skip-lists-are-the-wrong-default-for-matchmaking-queues-a-fenwick-tree-case-study?source=rss)