Promote-to-scale
What it is
One image that runs as a single-process demo monolith and, by configuration alone, fans out into independently scaled services.
Why it's different
No 'rewrite for production' cliff. The thing you saw in the demo is the thing that scales — so there's no second project hiding inside the first.
When it helps
Anywhere a stakeholder needs to see it working early, but the system must later carry real load.