I created a short tutorial on using sub domains to access services hosted within my home network, thought I would share it here in case anyone finds it useful
This is the first time I’ve made a technical tutorial so apologise if there are mistakes/its confusing, feedback will be appreciated


He does refer to the pi as a gateway, so you would be right about it coming before the router. In that case, the pi would be the device handling NAT and forwarding ports.
So I think he’s describing it accurately… it’s just not a common setup to see these days.