More nc, cut, grep, head, mkfifo, youtube-dl, and mplayer than anything about Bash.
The post is about doing all of this in pure bash builtins like /dev/tcp and bash functions. Not about gluing together tools which do the work.
> A purely bash web server, no socat, netcat, etc...
It's like replying to a thread about implementing a web server in C macros with how you implemented a music jukebox as a standard C program. Great, but also not the point or really even related.