A design system isn't built once. It's built to last for years.

A design system isn't built once. It's built to last for years.

Why a component library is only the beginning, how to build a shared language between design and development, and what changes when AI tools start taking part in the process.

Almost anyone who has worked on a digital product for a while knows the pattern. A button that looks slightly different on one screen, a form that behaves differently in another area, seven shades of grey and three different ways to show an error message.

Nobody planned it. The product simply grew. Another feature, another requirement, another developer asked for a quick fix. And slowly, without anyone noticing, the interface loses its consistency.

The usual answer is to build a Design System. You define colours, typography, components and usage rules, organise everything in a neat Figma library and feel that order has been restored. But this is exactly where the problem starts.

Because building a component library is relatively simple. Keeping it relevant, useful and up to date three years from now is a different challenge altogether.

After almost 20 years of working on digital products, on both the design and the development side, I have learned that a Design System's success isn't measured by how many components it has. It is measured by how much it truly becomes part of the way people work.

1. The problem isn't the design. It's the way we work.

When Stanley Wood joined Spotify's design team in 2012, he found a product suffering from inconsistency. Designers worked on different parts of the product, in teams and processes that weren't always in sync.

In his article "Design Doesn't Scale" he described how the real challenge wasn't only creating a unified visual language, but building a process that would let different teams work together. Out of that challenge grew GLUE, one of the industry's early and best-known design systems.

The key lesson of the story is that consistency isn't only about colours, buttons and spacing. It is the result of shared decisions, clear ownership and working processes. You can build the most precise component library, but if every team keeps solving the same problems differently, the system hasn't really achieved its goal.

2. Stop thinking in screens, start thinking in systems

Brad Frost, who developed the Atomic Design approach, put the idea in one simple sentence: "Build systems, not pages". Instead of designing each screen as if it stands alone, you plan the product as a system of components that repeat and fit together.

A button is not just a rectangle with text. It has sizes, states, behaviours, accessibility rules and responses to user actions. The same component has to behave predictably wherever it appears.

That is a significant shift in thinking. When you design a screen, the question is how it should look. When you design a system, the question is how each part should work, including in places that haven't been planned yet.

In my experience, this thinking matters especially in complex business systems. Such products keep evolving for years, and every small design decision can later affect dozens of screens and processes.

Good design solves today's problem. A good design system helps solve tomorrow's problems too.

3. The gap between Figma and code is where design systems fail

As someone who works in both design and front-end development, this is one of the most important topics for me.

Often the design system looks great in Figma, but the actual product tells a different story. The components are slightly different, the spacing doesn't match, some states were never built, and changes made in the design never reached the code. That creates two sources of truth, sometimes even three when the documentation is out of date too.

A healthy design system needs to connect three layers:

• Design Tokens. Shared definitions for colours, typography, spacing and radii, with a way to keep design and build in sync.
• Components in design. A Figma library with variants, states and defined behaviours that represents how the components are meant to work.
• Components in code. A consistent build of the same components, including loading, error, empty and disabled states, and all the cases that don't always appear in the beautiful showcase screens.

When names, rules and behaviours are in sync, communication between designers and developers becomes much simpler. Instead of explaining again how a button or a form should look and behave, everyone works from a shared language.

For me, this is one of the big advantages of combining design and development. Being able not only to plan a component, but also to understand how it will behave in a real product, how it will fit the existing architecture and how it can be maintained over time.

4. When AI joins the team, a Design System matters even more

In recent years, and especially with the rapid growth of AI tools for design and development, another change has arrived. Today you can ask an AI tool to produce a screen, a form, a table or even a whole user flow, and get a result within minutes.

But that speed brings a new problem too. If every request creates new components, different colours and other interaction patterns, inconsistency can spread at a pace we have never seen. This is exactly where a Design System becomes critical infrastructure.

Tools like Figma MCP can pass design context to AI-based development tools. When the system includes defined components, Design Tokens, usage guidelines and clear links between design and code, you can steer AI to use the existing language instead of reinventing it. The impact goes well beyond saving time.

In a world where AI can produce endless interfaces, a Design System is what helps a product keep one identity.

I think that in the near future, one of a product designer's key skills will be not only building a design system, but also defining the rules that let AI tools work within it in a controlled way.

5. A design system is a product in its own right

Nathan Curtis, one of the field's leading voices, put it well: "A Design System Isn't a Project. It's a Product, Serving Products". That distinction changes the whole way of thinking.

A project ends. It has a delivery date, a task list and a final result. A product, on the other hand, keeps evolving. It has users, changing needs, versions, new requests and problems to solve.

With a Design System, the users are the designers and developers in the organisation. And they won't use the system just because someone declared it the standard. They will use it if it is clear, reliable, comfortable to work with and, above all, saves them time.

That means treating it like any other product: understanding its users' needs, prioritising improvements, gathering feedback and measuring real usage. A component library nobody uses is not a success, even if it looks great.

6. Maintenance isn't the last stage. It's the real work.

The first version of a Design System is usually the exciting part. You build components, define rules, write documentation and feel that everything is finally in order.

But a digital product never stops changing. Processes are added, requirements change, new team members join and technologies are replaced. For the design system to stay relevant, it has to be managed over time. There are a few principles I believe in:

• Clear ownership. Someone needs to own the system, even if it isn't a full-time role.
• Versioning. Changes to components should be documented, so every team understands what changed and what it affects.
• A contribution process. When a team needs a new component, there should be a simple way to propose it and bring it into the system.
• Orderly deprecation. Old components don't disappear overnight. You mark them, offer alternatives and allow a gradual move.
• Measuring usage. Check how much of the system is really in use, and where teams are still building local solutions.

The principle is simple: a design system that doesn't evolve with the product gradually becomes another layer of work instead of a tool that simplifies it.

7. You don't need to start big. You need to start right.

One common mistake is trying to build a perfect Design System before you start using it. In practice, you don't always need a dedicated team or months of work.

You can start by mapping the existing product. Gather the buttons, fields, cards and messages, lay them side by side and spot where inconsistency has crept in. From there you define the basics: colours, typography, spacing and interaction patterns.

Pick a small number of components that repeat often, build them right in both design and code, and start using them in a real product. Only then expand.

I prefer a small, precise, well-maintained system over a huge library that nobody knows whether they can trust.

In the end, it's not a component library. It's a way of working.

After years of working on digital products, I am convinced the great value of a Design System isn't in the buttons, the colours or the components. It is in the ability of teams to work in a shared language, make decisions faster and build consistent products even as they keep growing.

In an age when AI can produce interfaces and code at unprecedented speed, the importance of this foundation only grows. Because the easier it is to create, the more important it is to know what is right to create, how things should work together and how to keep quality over time.

A design system succeeds not when it holds every possible component, but when it becomes the natural way the team designs and builds products.

And that is the difference between a library you finish building and a system that keeps creating value for years.