Veltos.Tech

Design

Design system

Also known as: design language system, UI kit, component library

Definition

A design system is a set of tokens, components and usage rules that exists simultaneously in the design files and in code, fixing colours, typography, spacing and element states so that a new screen is assembled from existing parts rather than reinvented.

A design system has three layers, and confusing them is the most common mistake. The bottom layer is tokens: named values for colours, sizes, typefaces, radii, shadows and spacing. The middle layer is components: button, input, card, modal, each with every state it can hold (default, hover, focus, pressed, disabled, loading, error). The top layer is rules: when to reach for which component, how the grid works, how labels and error messages are written. Without that top layer you get a parts bin rather than a system.

The return appears with volume and with time. A single landing page does not need a design system, because the system would cost more than the page. It starts paying off where there are dozens of screens, regular releases and several people on the product: a new screen then takes hours instead of days, a button colour change propagates everywhere through one token, and developers stop asking what the spacing here should be and inventing an answer. A separate benefit is testability: a component with documented states is verified once rather than on every page.

The main trap is a design system that exists only in Figma. Once the component library in the design files and the code diverge, every screen still gets built from scratch and the system turns into attractive documentation nobody opens. The working arrangement is shared tokens feeding both the design files and the styles in code, plus a live component library the front end genuinely references. The second trap is trying to describe everything at once: a system starts with the ten to fifteen most frequent components and grows with real demand.

Related terms

Related services

Read more

Need this done, not just defined?

We do this work, not only write about it. Describe the task and we will scope it and send a staged estimate.