Hypixel PE was a project to bring Hypixel to the Bedrock version of Minecraft to make the server available on phones. It managed to reach 18,000+ concurrent players.
This was a 3-man project. It was a challenge because the server platform we were using was in C# rather than Java, with a totally different API.
My part in the project was to build everything on the game server:
https://hypixel.net/threads/hypixel-pocket-edition-launch.465874/
Interestingly enough, lots of features which came from PE became staples of the main server, like clickable NPCs for games, hologram leaderboards, using Redis, Arena became The Pit…