I’ve always used an authoritative DNS server as my go to. Almost all code I write has to do some kind of network IO, so learning the nuances of how TCP and UDP

I’ve always used an authoritative DNS server as my go to. Almost all code I write has to do some kind of network IO, so learning the nuances of how TCP and UDP sockets work is important to me. It also happens to touch on bitwise operations, data structures, and parsing, so it’s a great project to quickly become competent in a language (assuming you already know DNS well at a protocol layer).