By the end of September, roadmaps can start to sound more certain than the product really is. I like to interrupt that with a prototype before the plan gets too heavy.

The prototype does not need polish. It needs to expose flow, dependency, and friction. A few linked screens can reveal whether the idea has a natural path or whether the team is relying on explanation to make it work.

I have learned to prototype the riskiest moment first. If the hardest transition feels clumsy, the rest of the roadmap should probably slow down.

This is not about blocking ambition. It is about giving planning a closer relationship with the actual user experience.