Clean Architecture in Front-End Development

#frontend #cleanarquitecture #architecture #webdev

Clean Architecture, introduced by Robert C. Martin, is a software design philosophy that emphasizes the separation of concerns and independence from frameworks or tools.

While it originally gained traction in back-end development, it's increasingly being adapted to front-end projects, especially as these applications grow more complex.

In this article, we'll break down what Clean Architecture means for front-end developers, explain its core layers, and show you how to apply it in real-world UI codebases.

What is Clean Architecture?

Clean Architecture organizes code into layers, forming concentric circles. Each layer depends only on the one inside it. This approach allows you to write code that is independent of frameworks, easy to test, and resilient to change.

The main idea:

Your business logic should not depend on frameworks, databases, or UI code. These are implementation details that can change.

Core Layers

The traditional Clean Architecture model maps layers this way:

Image from Clean Architecture on Frontend, Alex Bespoyasov

Entities (Domain Layer): This layer is Framework-agnostic. It is for core business logic and domain models and it contains rules that rarely change

export type User = {
  email: string;
  password: string;
};

export const isValidEmail = (email: string): boolean => {
  return email.includes('@');
};

Use Cases (Application Layer): The use cases layer orchestrates how data flows between the domain and UI and it encapsulates application-specific rules

export const loginUser = async (
  email: string,
  password: string
): Promise<boolean> => {
  if (!isValidEmail(email)) {
    throw new Error('Invalid email');
  }

  const user: User = { email, password };
  return await loginApi(user);
};

Interface Adapters (Presentation Layer): Includes components, view models, presenters...

export const LoginForm = () => {
  const [email, setEmail] = useState('');
  const [password, setPassword] = useState('');

  const handleLogin = async () => {
    try {
      const success = await loginUser(email, password);
      alert(success ? 'Logged in!' : 'Login failed');
    } catch (error) {
      alert((error as Error).message);
    }
  };

  return (
    <form onSubmit={(e) => e.preventDefault()}>
      <input
        type="text"
        placeholder="Email"
        value={email}
        onChange={(e) => setEmail(e.target.value)}
      />
      <input
        type="password"
        placeholder="Password"
        value={password}
        onChange={(e) => setPassword(e.target.value)}
      />
      <button onClick={handleLogin}>Login</button>
    </form>
  );
};

Frameworks & Drivers (Infrastructure Layer): These should only interact with your app through interfaces or adapters such as axios, fetch, local Storage...

export const loginApi = async (user: User): Promise<boolean> => {
  const response = await fetch('/api/login', {
    method: 'POST',
    body: JSON.stringify(user),
    headers: {
      'Content-Type': 'application/json',
    },
  });

  return response.ok;
};

Benefits

Testability: You can test business logic without a browser or DOM.
Maintainability: You can swap frameworks or APIs with minimal impact.
Scalability: You can grow the codebase easily.

Conclusions

Clean Architecture isn't just a pattern: it's a mindset. In front-end development, it helps keep your application modular, testable, and framework-agnostic, which is especially valuable in a fast-evolving JavaScript ecosystem.

Even if you don’t adopt all its principles at once, gradually introducing its ideas can lead to cleaner, more resilient code.