The server was made upon a commission from Evident. It was made using Dragonfly, a server software library made in Go.
Dragonfly is a heavily asynchronous server software for Minecraft Bedrock Edition written in Go. It was written with scalability and simplicity in mind and aims to make the process of setting up a server and modifying it easy. Unlike other Minecraft server software, Dragonfly is generally used as a library to extend.
The server went through a re-write, which increased the server’s stability during large events. In the huge list of things commissioned by Evident, one of them was straight up adding hacks to the server, which led to this amazing video being made: