How do you frame what needs to be designed before development?

You first keep critical journeys, essential roles, the data without which the product does not work, and the validations that genuinely protect the business.

The areas where decisions are still unclear, the most used views, sensitive journeys, and the moments where several roles intersect or block each other.

Yes on some areas. But critical journeys, recurring components, and structuring choices benefit from being defined more precisely before build.

By linking every design effort to a real product decision: a role, a journey, a business rule, an approval, or a comprehension risk.

As early as possible on trade-offs that affect complexity, integrations, existing debt, or the ability to ship a realistic V1.

Depending on the topic: journey maps, wireframes, targeted mockups, interface rules, V1 decisions, prioritization, and open points to arbitrate.

You can start again from priority use cases, clarify the V1 that is truly being used today, and restore order before adding new layers.

The main benefit is avoiding the shift of ambiguity into build. Useful decisions are made earlier, and the team moves with a more defensible scope.