The problem
To sell software you need somewhere to run it. Renting a cloud for every experiment gets expensive quickly, and that makes trying something out uncomfortable, which is the wrong threshold to have.
Approach
Outbound connections only. There are no inbound ports open to the house and no forwarding in the router. Everything reaches the internet through an outbound tunnel and a single reverse proxy that knows each hostname.
What runs on it
One container per service, a reverse proxy in front of all of them, and read-only web roots for the static sites, so a web server can never write to what it serves. The configuration is version controlled and backed up on a schedule.
This site runs on it. So do the games at games.sesnas.com, and SES Quality, the first product.
Outcome
Publishing a change takes one command from my laptop. That made trying things cheap enough that things actually get tried.
What I learned
That the constraint which made it safe also made it simple. Once no ports were allowed to open, a series of other decisions fell into place on their own.