A design system isn't a sticker sheet of components — it's the contract between design and engineering. When that contract lives in screenshots, it rots the moment someone ships a one-off.
We start with tokens: colour, type, spacing and radius defined once, named by intent (surface, ink, accent) not by value. Designers and engineers reference the same names, so a brand tweak is a one-line change instead of a week of find-and-replace.
Components come next, built straight from the tokens and documented with real, copy-pasteable code. If a component can't be assembled from tokens, that's a signal the system is missing something — not a reason to hard-code a hex value.
The payoff compounds. New screens are faster to design, reviews get shorter, and accessibility (contrast, focus, hit targets) is baked in once rather than re-litigated per feature. The system becomes the path of least resistance — which is the only way adoption ever sticks.