Design systems: start at divergence, not day one

What is the short answer?

A design system pays for itself the second time two people build the same button differently. Until a team ships weekly across surfaces, a system is overhead. The trigger is divergence: inconsistent spacing, five greys, three primary buttons. That is the moment, not before.

What belongs in version one?

Tokens, three components, and one rule. Colour and type tokens, button-input-card built properly, and the rule that everything ships from the system or updates it. A twenty-component library nobody maintains is worse than no library — it becomes a museum of good intentions.

Who owns it?

Someone named, with hours attached. Ownerless systems rot within a quarter as teams fork components under deadline. The owner reviews additions weekly, prunes quarterly, and says no more than yes. A system is a product with users — your own team — and needs a product owner.

How do you know it works?

Screens ship faster and look like one product. Measure time from brief to shippable screen before and after, and audit quarterly for forks. If velocity rises and divergence falls, the system earns its maintenance. If not, it is decoration.