I have a few single board computers at home that I want to try hosting some public facing stuff with, but what’s the best way to deal with the fact that my home internet is not on a static IP? Would I have to host my site from a DynDNS domain and hope that when the IP changes, the DNS caches of users expire quickly enough to keep them connected?
Check how often your home-ip really changes. If you have router running 24/7 then likely it will not change very often. Some ISP enforce a disconnect every 24h but even then the IP sometimes stays the same.
On my connection I get the same IP for months without change unless I specifically turn off my router and wait >1h for the lease to expire.
So usually a dynDNS service will work fine as the updates propagate quite quickly. You can dynDNS your own domain name directly, just switch to a name-server with dynDNS functionality like those offered for free by 1984.is. But there are also others, check your router software. OpenWRT derivatives usually support dynDNS out of the box with some pre-configured providers.