Who your users are, what they are afraid of and what they will never admit on a survey.
What the product has to tell them, in what order, and at which moment it matters.
The result the user wants and the result the business needs, named separately, then deliberately aligned.
Constraints and friction points written down before design starts, not discovered in QA the week of launch.
One sentence the whole team can repeat. If they cannot say it, the interface will not show it.
Where the effort goes, and just as importantly, what we are deliberately not building.
The handful of numbers that will decide, honestly, whether this worked.
