As UI design and development has evolved over the last few decades, so too has the complexity and scale of websites and digital products. It's not uncommon for applications to have thousands of different pages, design patterns, and individual design components and visual elements.
But how do world-class companies like Apple, Google, and Spotify build and scale their digital experiences efficiently with thousands of employees worldwide?
In this short guide, we'll define design systems and user interface kits (UI kits), explain the benefits of using and creating a design system, review its pros and cons, and discuss the essential differences between UI kits and design systems.
Let's start by exploring what a design system is.
What is a design system?
A design system is a collection of reusable UI elements that product teams use and build on to create a consistent user experience across digital products.
A design system keeps the visual design and visual language of digital products consistent, acting as a "single source of truth" for product teams, designers, and developers.
A great way to think about design systems is as the "design language" and "design philosophy" of a product or company:
- Various UI components
- Code components and code snippets
- Design files and design elements
- Style guides (typography styles, color palettes etc.)
- Design guidelines (design patterns, visual styles, and best practices)
- Design process and visual design guidelines
- Content guidelines and style guides
- Other design resources (documentation, articles, design principles, and design philosophy guidelines)
A design system is more than just the building blocks of a product; it acts as a design philosophy and the visual language of a product and brand. As a single source of truth, an effective design system keeps entire product and design teams on track and consistent while reducing design debt along the way. When design teams have clear best practices to reference, it's easy to create great user experiences.
How are design systems used?
Design systems act as a powerful North Star that can be referenced by a company's UX designers, UI designers, developers, and even marketers and content writers simultaneously, giving them instructions on developing a product's design consistently.
For example, suppose a developer needs to create a dropdown menu within a new feature in a product. While small design components like dropdowns and input fields may seem simple on the surface, they contain dozens of small design decisions. The developer will quickly run into a few questions:
- What does this component look like?
- How big is this component?
- What is the color palette for each UI element?
- How are the UI elements in the component spaced and sized?
- How does it open?
- What is the hover transition?
- What icons, typography, and colors should I use?
- What should the copy say? Are there content guidelines?
- What does the empty state look like?
- Do I need a designer to create one from scratch?
- Where can I find design files for this component?
These are incredibly important questions, but chances are a designer has already thought about these and designed a dropdown component for another page. With an existing design system in place, the developer can simply copy the code snippet of an existing dropdown component, and ensure that every aspect of it — spacing, typography, UX, hover states, etc. — behave exactly how the designer intended.
Similarly, if product designers or design team members want to make a change to a dropdown component, they can make these changes in one place and ensure the code components are updated so the change is reflected everywhere that component is used.
While working from a design system with existing design components may sound like a constraint, it actually removes decision fatigue and allows product teams to work faster and design and build better. Without a defined design system, you end up with messy and inconsistent visual styles and designs. Coming back to the example above; if a simple dropdown component looks and behaves differently across a product, it creates a confusing and poor user experience.
Do you need a design system?
Building and maintaining a design system can be a lot of work. Some design systems are simple and easy to maintain. Some are large enough that companies hire dedicated design system designers and developers who focus on simply maintaining them. You may be wondering whether or not you actually need a design system...
The answer, for the most part, is to avoid design debt. In simple terms, design debt is the accumulation of all the inconsistencies, imperfections, poor user experiences, and design processes that were skipped in order to reach short-term goals. Design debt is all the shortcuts a team has taken along the way that need to be addressed.
Accumulating design debt over time is natural and happens to every product. It’s a side effect of development. The important thing is that it is understood and managed before the cost, time, and resources required to go back and "fix" these problems are too high. Thousands of companies simply ignore it for too long and get flanked by competitors with far superior design and user experience and are unencumbered by design debt.
Building and maintaining a design system, even a simple one, from the start of your development process allows product teams to monitor and address design debt issues as they arise by keeping the design process consistent. We'll get into the benefits of using a design system a little more later.
It's important to note that you don't have to build a design system from scratch. Using a resourceful and high-quality design system is often a great way to start because they come with a large portion of already existing UI components, design guidelines, design files, and even code components and code snippets.
With an effective design system in place, UI designers and product designers will be able to focus on finishing up their prototypes and improving their usability and functionality, rather than painstakingly recreating the same components over and over. On the other hand, developers won't need to spend hours on recreating existing code components — they'll already be available as part of the design system.
Lastly, product managers will spend less time putting out fires and fixing design debt problems, so they can focus more resources on improving the products and new features.
If your product and design team is not using a design system to speed up your design and development workflow, chances are a competitor is and these small efficiencies compound over time until they're too much work to fix.
Pros and cons of using a design system
Read on to learn more about a design system's positive and negative aspects.
- Design (and develop) products faster: By using a design system, your team won't need to redesign and rebuild design components repeatedly and can move much faster than competitors.
- Save time and focus on important details: Save time rebuilding components and figuring out tiny details and instead focus resources on meaningful design decisions and improving other aspects of the product.
- Improved consistency: Keep everything consistent, organized, and maintainable right from the start, so everyone involved in the design process can stay on the same page.
- Quickly and easily make changes: Making changes to specific design components doesn't have to be complicated, with an efficient design system, product teams can make changes in one place and cascade these changes everywhere across the product.
- Create a unified and polished brand: By using a design system, you'll be able to unify a product's branding faster and speed up the product's development.
- Simplify quality control: With a design system in place, designers and developers can reference a single source of truth to simplify design reviews and spot inconsistencies, drastically simplifying the design and development process.
- Decrease in development expenses: Product development is expensive and time-consuming. Working from an existing design system saves time and money usually wasted on inefficient web development and fixing design debt.
- Develop a consistent outlook: By keeping everything consistent for everyone on the team, a design system helps leaders develop a clear brand and vision, which helps to create a long-term brand recognition strategy.
- Multi-functional participation: Everyone involved in the product design process can participate and collaborate without missing any part of the project — all the product teams will be up to date.
- Take time to maintain: Design systems, like companies, are always evolving and changing. As such, product teams need to dedicate time and resources to maintaining and improving design systems.
- Decrease in creativity: As products scale, so too does their design system. With already established rules, content guidelines, and reusable design components, design systems can sometimes feel like they are limiting creativity.
- Less exploration and research: Similarly, when large teams use a design system, designers and developers can feel less inclined to research alternatives or explore alternative ideas and approaches.
- Takes time to learn: When implementing a design system or adapting an existing design system, some of your team members may have a difficult time adopting the new approach. This may lead to decreased efficiency and slow your design's progress rate. Thankfully, this is usually only short-term!
Examples of design systems
Many companies decide to make their design systems publicly available and even open source. These are great design resources for exploring how world-class companies think about design and approach design systems and their design and development processes. Here are some great public design systems:
Google Material Design 3
The Material Design System by Google is a unified system that combines theory, resources, and tools for crafting digital experiences. Material 3 is the latest version of Google’s open-source design system and contains a huge library of UI components, icons, styles, source files, starter kits, code components, etc.