What is a frontend?

Frontend: definition and scope

The term frontend describes the presentation layer of a piece of software. On the web, it consists of three basic building blocks: HTML for structure and content, CSS for styling and layout, and JavaScript for interaction and dynamic features.

Its counterpart is the backend, which processes and stores data on the server. Frontend development turns the design—from Figma, for example—into working code and ensures that the interface is easy to use on every screen.

How a modern frontend works

When a user opens a page, the browser loads HTML, CSS, and JavaScript and builds the interface from them. In web applications, data is then loaded from the backend via an API, so content updates without the entire page reloading.

For larger applications, frameworks such as React, Vue, or Angular are used. They break the interface down into reusable components—a button, a form, a product card—and keep large projects maintainable.

• Responsive design for smartphone, tablet, and desktop
• Performance: fast loading times, good Core Web Vitals
• Accessibility in line with WCAG, e.g., keyboard navigation and contrast
• Clean structure for search engines and AI search

Benefits of a good frontend and common pitfalls

The frontend determines the first impression—and whether visitors submit an inquiry, complete a purchase, or bounce. A clear, fast interface also reduces support and training effort, especially for internal applications.

Common pitfalls include bloated pages with too much JavaScript, a lack of optimization for mobile devices, and poor accessibility. The latter is not just a matter of usability: since June 2025, many digital products and services in Germany have been subject to the requirements of the German Accessibility Strengthening Act (BFSG). Whether your offering is affected should be checked on a case-by-case basis—this note does not replace legal advice.

Real-world example: a new frontend for an existing application

A service provider has been using internal software for years whose interface only works properly on a desktop. Instead of rebuilding the entire system, it gets a modern React-based frontend that talks to the existing backend via an API. Employees can now also process orders on a tablet while on the go.

A new frontend makes sense when the design and usability are outdated but the data behind them is sound. Nano Concepts builds frontends together with its partner agency LOMA DESIGN—design and development from a single source.