As a frequent user of the backend (Connect), I am skeptical that this is source that you want to reproduce (unless you're a scammer).
The pattern itself is a little bit different, has some conceptual overhead, but it's also fairly clean and scaleable.
I’ve been staring at Apple source code (the stuff they let The Great Unwashed see), for almost forty years.
It’s always been very polished, well-structured, well-documented, succinct, and beautifully written.
It’s been an inspiration for my own work. I have always striven to emulate them.
That’s why it’s so shocking for me to encounter the terrible quality of the Connect backend. It’s quite painful, and disappointing.