Where the people see a simple game, I see a fantastic cluster, SIMD and MIMD, large part with multiple part, and various knowledge sector.
Firstly the project is dev into C and C++ (async + epoll), this allow with good knowledge of complilation processus, be fast near assembly speed. The server's code scale well on 256 core, on cluster with 50k nodes
The code can be compiled into webassembly, android, windows, linux, BSD, Mac OS X, ... on ARM, x86, RISC-V, MIPS
The dev environment and production is backed on Confiared data center, one ARM server from 16 core to x86, CatchChallenger is provided as SaaS product, in this mode, it consume Kb of disk space, Kb of memory by connected player.
Large work around the protocol as compression, async, cache mechanism was inspiration to the http2 protocol, the protocol is designed to minimize the bandwidth to allow host your server into your home.