Just as an update, this site was served with caddy server for about a year, without issues, primarily for the letsencrypt integration (it was one of the first to have it). I've now switched to serving directly with the latest version of Go in a single process, and will soon be enabling autocert support. As @matt says above though, it has been used on some large-ish sites for some time now, so anyone wondering if it is production ready, the answer at this point is definitely yes.