Model state before polishing the interface

A polished order page does not answer who can change an order, which transitions are valid, or what happens when inventory changes halfway through checkout. Those are domain questions, not visual states.

Writing the lifecycle first exposes ambiguity while it is still inexpensive to resolve.

Every important state needs an owner, allowed transitions, authorization rules, and an audit trail. The UI can then render capabilities from the same language the backend enforces.

• Name states after domain meaning, not button labels.
• Reject invalid transitions at the service boundary.
• Record who changed state and why.
• Test transitions independently from presentation.

Explicit state models make APIs easier to document, permissions easier to review, and interfaces easier to keep consistent. The result is not more architecture—it is less accidental complexity.