Tonight I did some research into using WireGuard VPN.
One commenter suggested using Tailscale - https://tailscale.com/ - because their code is open source, and it turns out it’s written in Go.
After looking at the code I immediately thought this is something that could be done well in Crystal too, but was never considered for use by that project.
As WireGuard is an open protocol, and will likely become the most widely used VPN, this is the type of use case that a Crystal implementation could become a ''killer app" for it, and showcase its use to the general public.