What is the best way to generate a global leaderboard for our game?

I work on a ROBLOX game called RoBeats CS, which is a VSRG (vertical scrolling rhythm game). We have hundreds upon thousands of scores in one table. Every player gets his/her own Skill Rating, which is calculated by the Rating of the best 25 scores that player made. What is the best way to do a ranking system so that players can have their own rank? Do note that most of my backend is done and I mostly know what I’m doing. I just don’t know the best approach. Thanks for any help I can get.