A Design System is a collection of reusable components. Using the atomic design methodology, Atoms, Molecules, Organisms, Templates, and Pages are used together to create a unified Design System in a more deliberate and hierarchical manner. It acts as a single source of truth for the building blocks of your design, including all the foundations, components, patterns, and assets. With a Design System, you can build products better, faster and it results in a cohesive experience for the user.

Even though having a Design System makes the life of the designers as well as the developers easier, there are several instances where having a design system might not be the best solution, for example,

• when the project team is small and communicates well
• when the development team is not actively engaged in development (ie: CMS gets built and the work is done)
• if the business has limited resources and funding

The generic convention is to design the Design System at the very early stages of a project and let it evolve and mature throughout the project life cycle. For a product that has already been developed, creating a Design System might not be the best approach. But yet it can be supportive when the system needs a re-design or a revamp because some principles might still be valid.