Modern React Patterns in 2024: Building Scalable Applications

React continues to evolve, and with it, the patterns and practices that define modern web development. At Kodely, we’ve been working with the latest React features and architectural approaches to build applications that are not just functional, but maintainable and scalable.

The Current State of React Development

The React ecosystem in 2024 is more mature than ever. With React 18’s concurrent features, Server Components, and the growing adoption of TypeScript, developers have powerful tools at their disposal for building sophisticated applications.

Essential Patterns for Modern React

1. Server Components and RSC Architecture

React Server Components have revolutionized how we think about rendering and data fetching:

// Server Component
async function BlogPost({ slug }: { slug: string }) {
  const post = await fetchPost(slug);
  
  return (
    <article>
      <h1>{post.title}</h1>
      <PostContent content={post.content} />
    </article>
  );
}

2. Custom Hooks for Logic Abstraction

Custom hooks remain one of the most powerful patterns for code reuse:

function useLocalStorage<T>(key: string, initialValue: T) {
  const [storedValue, setStoredValue] = useState<T>(() => {
    try {
      const item = window.localStorage.getItem(key);
      return item ? JSON.parse(item) : initialValue;
    } catch (error) {
      return initialValue;
    }
  });

  const setValue = (value: T | ((val: T) => T)) => {
    try {
      const valueToStore = value instanceof Function ? value(storedValue) : value;
      setStoredValue(valueToStore);
      window.localStorage.setItem(key, JSON.stringify(valueToStore));
    } catch (error) {
      console.error(error);
    }
  };

  return [storedValue, setValue] as const;
}

3. Compound Components Pattern

This pattern provides flexibility while maintaining a clean API:

const Disclosure = ({ children }: { children: React.ReactNode }) => {
  const [isOpen, setIsOpen] = useState(false);
  
  return (
    <DisclosureContext.Provider value={{ isOpen, setIsOpen }}>
      {children}
    </DisclosureContext.Provider>
  );
};

Disclosure.Button = DisclosureButton;
Disclosure.Panel = DisclosurePanel;

TypeScript Integration Best Practices

Strict Type Safety with Generics

interface ApiResponse<T> {
  data: T;
  status: 'success' | 'error';
  message?: string;
}

function useApi<T>(url: string): {
  data: T | null;
  loading: boolean;
  error: string | null;
} {
  // Implementation
}

Performance Optimization Strategies

1. Smart Memoization

const ExpensiveComponent = memo(({ data, onUpdate }: Props) => {
  const expensiveValue = useMemo(() => 
    computeExpensiveValue(data), [data]
  );
  
  const handleUpdate = useCallback((id: string) => {
    onUpdate(id);
  }, [onUpdate]);
  
  return <div>{expensiveValue}</div>;
});

2. Code Splitting and Lazy Loading

const LazyComponent = lazy(() => import('./HeavyComponent'));

function App() {
  return (
    <Suspense fallback={<Loading />}>
      <LazyComponent />
    </Suspense>
  );
}

State Management Evolution

Zustand for Simple State

interface BearStore {
  bears: number;
  increase: (by: number) => void;
}

const useBearStore = create<BearStore>()((set) => ({
  bears: 0,
  increase: (by) => set((state) => ({ bears: state.bears + by })),
}));

React Query for Server State

function Posts() {
  const { data, isLoading, error } = useQuery({
    queryKey: ['posts'],
    queryFn: fetchPosts,
    staleTime: 5 * 60 * 1000, // 5 minutes
  });

  if (isLoading) return <Loading />;
  if (error) return <Error error={error} />;
  
  return <PostList posts={data} />;
}

Testing Modern React Applications

Component Testing with Testing Library

test('should update count when button is clicked', async () => {
  render(<Counter initialCount={0} />);
  
  const button = screen.getByRole('button', { name: /increment/i });
  const count = screen.getByTestId('count');
  
  expect(count).toHaveTextContent('0');
  
  await user.click(button);
  
  expect(count).toHaveTextContent('1');
});

Looking Ahead

The React ecosystem continues to evolve rapidly. Key areas to watch include:

• React Compiler: Automatic optimization of React components
• Concurrent Features: Better user experiences with non-blocking rendering
• Server Components: Continued evolution of the RSC pattern
• Streaming: Improved loading experiences with Suspense

Conclusion

Modern React development in 2024 is about leveraging the right patterns for the right problems. At Kodely, we focus on building applications that are not just technically sound but also maintainable and scalable for the long term.

The key is to stay informed about new patterns while being selective about adoption. Not every new pattern needs to be used in every project—the art is in choosing the right tools for the job.

Want to discuss React architecture for your next project? We’d love to help you build something amazing.