I think one of the nice examples is agentic design systems.

On one hand, you set some boundaries on user interface layout, flow, allowed components, etc. so that the interface looks & feels like belonging to the same product every time.

On the other hand, you may decide to leave more "creative freedom" in some other areas. The fun part comes when you let it work in semi-realtime in production, and get sort of generative/organic UI. I enjoy experimenting with that these days.