I've typically leaned towards Python for my agentic programming, because the LLMs have been good at it and I'm familiar with it if I need to take a look. But I'm just finishing up an apt-cacher replacement and decided to use golang and the experience has been really great.

I'm using CC+Opus 4.7 max effort, and it's produced a working apt cacher from the first phase of development, so far there have only been a few things I've had to ask it to fix. This is over ~52KLOC (counted by "wc -l"), going on day 3 of it working on it. This includes: caching proxy, garbage collection, "http://HTTPS///" kludge (apt-cacher-ng semantics), MITM https proxy, admin website + metrics, deep validation of metadata and rejecting invalid updates, snapshots of upstream state and delayed metadata update until "hot packages" are available after metadata update...

10/10, would go again.

FYI: My agent loop is: "Work on next step, have codex review it, compact", and then a couple rounds at the end of a phase to review the code against the spec, and a couple rounds at the beginning of a phase to create the spec.