I've worked extensively with the Celeste Community as both an event organizer and the lead developer of our restreaming tech package from 2022 to 2023.
This package allowed us to run hundreds of livestreamed speedruns and player-vs-player tournaments of the amazing game Celeste.
The main functions of this package are to facilitate producers (who we call restreamers) to manage and display player data on our livestreams, as well as live video feeds of the players from twitch.tv and tournament related data like scores, team names etc.
This package has been and is currently used for regular 16 person bracket tournaments, very large 100 player speedrun competitions, as well as special events like our Celeste Time Trials (where complexities arose from having to have continuous content with changing feeds, integrated leaderboard data and all without any downtime at intermissions) and our yearly charity marathon Archiethon (where we integrated a ton of donation and incentives data with interesting graphics, as well as setting up accommodations for many different formats of play during the marathon and dealing with having hosts, commentators and players on screen at once).
I put a lot of work into this package, notably making the organizer's workflow easier, but it must be noted that I build upon work from predecessors in the community and couldn't have done it without help from other super helpful people on the tech team (see Additional Credit panel in our twitch about section).
This package is currently closed source without a public package available to share. Sorry! Recordings of our tournaments where my tech is being used can be found here youtube.com/@CelesteCommunity.