Design systems are, in practice, a set of components, patterns and principles to help teams maintain consistency across a company's digital ecosystem. It sounds simple, but it also seems to be the foundation of UX/UI architecture - it influences the pace of product development and how consistently a company communicates its visual identity.
In practice, a design system is a structured reusable library: buttons, forms, tabs, navigation elements and technical documentation showing how to implement them. Tools such as Figma, Sketch or Adobe XD make it easy to create and synchronize libraries between designers and developers, while Storybook, Zeroheight or Notion are used to share knowledge across the team. Just remember - documentation must be alive and supervised; without it, the system will quickly become a collection of obsolete components.
The technological benefits are tangible: developers get ready-made components for React, Vue or Angular, which can speed up development by up to 40% and significantly reduce code duplication. Designers get a consistent library, so inconsistencies between sections of the site are less likely to occur. For SMEs, the design system is particularly useful for expansion - the homepage, customer panel and mobile app can all use the same components. In my experience, the investment usually begins to pay off by the second project, although it is worth bearing in mind the initial cost of implementation and the need for ongoing management of the system.