How I turned Zig into my favorite language to write network programs in

Summary

2025-10-26 How I turned Zig into my favorite language to write network programs in I’ve been watching the Zig language for a while now, given that it was created for writing audio software (low-level, no allocations, real time). I never paid too much attention though, it seemed a little weird to me and I didn’t see the real need. Then I saw a post from Andrew Kelley (creator of the language) on Hacker News, about how he reimplemented my Chromaprint algorithm in Zig, and that got me really interested. I’ve been planning to rewrite AcoustID’s inverted index for a long time, I had a couple of prototypes, but none of the approaches felt right. I was going through some rough times, wanted to learn something new, so I decided to use the project as an opportunity to learn Zig. And it was great, writing Zig is a joy. The new version was faster and more scalable than the previous C++ one. I was happy, until I wanted to add a server interface. In the previous C++ version, I used Qt, which might seem very strange for a server software, but I wanted a nice way of doing asynchronous I/O and Qt allowed me to do that. It was callback-based, but Qt has a lot of support for making callbacks usable. In the newer prototypes, I used Go, specifically for the ease of networking and concurrency. With Zig, I was stuck. There are some Zig HTTP servers, so I could use those. I wanted to implement my legacy TCP server as well, and that’s a lot harder, unless I want to spawn a lot of threads. Then I made a crazy decision, to use Zig also for implementing a clustered layer on top of my server, using NATS as a messaging system, so I wrote a Zig NATS client, and that gave me a lot of experience with Zig’s networking capabilities. Fast forward to today, I’m happy to introduce Zio, an asynchronous I/O and concurrency library for Zig. If you look at the examples, you will not really see where is the asynchronous I/O, but it’s there, in the background and that’s the point. Writing asynchronous code w...