React.js in 2025

State of the Art in 2025

What is React today?

React is a JavaScript library built around components, created by Meta, and used to build dynamic user interfaces. Based on a declarative model and the Virtual DOM, it relies on functional components and unidirectional state management. Today, React is most often used with hybrid frameworks such as Next.js or Remix, combining SSR, SSG, and RSC.

Key Concepts

Functional components and hooks (useState, useEffect, useContext, etc.)
JSX: syntax combining HTML and JS
Virtual DOM and reconciliation
One-way data flow (props)
Declarative and reusable composition

Recent Evolutions

React 18: Suspense, Automatic Batching, Concurrent Rendering
Server Components (RSC): server-side execution to reduce client-side JS
Streaming SSR: progressive HTML rendering
useTransition and useDeferredValue: finer update control

Enterprise Usage

React is omnipresent:

SaaS and dashboards: complex state management and dynamic UIs
E-commerce / showcase sites: SEO + SSR via Next.js
Mobile apps: React Native / Expo
Design systems: Storybook, MUI, Chakra UI
Hybrid apps: front + back via Next.js (API Routes, Edge functions)

Advanced Features Used in Enterprise

Rendering and Performance

Concurrent Rendering (React 18): interruptible, smoother rendering
Suspense & lazy loading: progressive component loading
React Server Components (RSC): server-side computation, smaller client bundle
Streaming SSR: improved TTFB
Transitions (useTransition): prioritize updates

Advanced State Management

Context API + useReducer for local logic
Redux Toolkit: the simplified de facto standard
Zustand, Jotai, Recoil, Valtio: atomic state management
TanStack Query / SWR: server state, caching, network synchronization

Architecture Patterns

Custom hooks (encapsulated business logic)
Compound Components, Render Props, HOCs
Atomic Design + Storybook
Controlled vs Uncontrolled Components for forms

Optimization and Scalability

Memoization (useMemo, useCallback, React.memo)
Error Boundaries
Code splitting (React.lazy, dynamic imports)
Bundle analysis (Webpack, Vite, Rollup)

Ecosystem and Integration

Next.js: SSR, SSG, ISR, RSC
Remix: data loaders and web standards
GraphQL clients: Apollo, Relay
React Native: mobile + web shared logic
Micro-frontends: Module Federation

Testing and Quality

Jest + React Testing Library
Cypress / Playwright for E2E
Lint a11y + ESLint hooks
Storybook for visual validation

Accessibility and i18n

React Aria, Radix UI, Headless UI
i18next + react-i18next

Monitoring and Deployment

React Profiler
Sentry / Datadog / LogRocket
Feature flags: LaunchDarkly, Split.io

Common Issues Encountered

Performance and Unnecessary Re-renders

Re-renders caused by un-memoized props or global context
Overuse of hooks without optimization

Solution: memoization, profiling, component splitting

Complex State Management

Confusion between local, global, and server state

Solution: separate UI state (local) from server state (React Query, SWR)

Misunderstood `useEffect`

Missing or excessive dependencies → infinite loops

Solution: custom hooks and strict ESLint rules

SEO and Indexing

Pure CSR invisible to bots

Solution: SSR / SSG via Next.js or Remix

Heavy Bundles

Unnecessary libraries, no code splitting

Solution: dynamic imports, regular audits

Fragile Tests

Volatile snapshots, logic coupled to UI

Solution: user-centric testing

Neglected Accessibility

Solution: a11y audits, Radix UI, ESLint a11y

Complex Ecosystem

Solution: standardize stack (TypeScript, Next, Zustand/Redux, Query)

Difficult Migrations (legacy)

Solution: incremental refactor, testing, stable CI

Lack of Conventions

Solution: feature-based architecture, atomic design, Storybook

React “Anti-Problems” Checklist

Performance & Rendering

Split large components
Memoize functions and objects (useCallback, useMemo)
Use React.memo on heavy components
Virtualize large lists
Use useTransition and useDeferredValue for smooth updates

State Management

Separate UI state from server state
Use TanStack Query / SWR for server state
Use Redux Toolkit or Zustand for global state
Normalize data structures

Hooks & Effects

Limit useEffect to asynchronous logic
Always clean up (return cleanup)
Move business logic to custom hooks

Accessibility

Visible, ordered keyboard focus
Use Radix UI / React Aria
Lint with eslint-plugin-jsx-a11y

Testing

React Testing Library (user-focused tests)
Cypress / Playwright for E2E
Mock APIs with MSW
Avoid unnecessary snapshots

Code Splitting & Bundle

Use React.lazy / dynamic() for heavy modules
Audit with Webpack Bundle Analyzer / Vite Visualizer

Security & SEO

SSR / SSG / ISR with Next.js
Avoid dangerouslySetInnerHTML without sanitization
Use HttpOnly cookies for tokens
Configure CSP and security headers

Architecture & Conventions

Organize by feature (features/todo)
Use custom hooks for reusable logic
Atomic Design + Storybook
Enforce strict TypeScript (strict: true)

Monitoring & DX

Sentry / Datadog / LogRocket for error tracking
React Profiler for performance
Feature flags for progressive deployment

Conclusion

React is now a complete ecosystem, not just a library.

Its success in enterprise projects relies on:

Its flexibility (client, server, mobile)
Its technological maturity (RSC, Suspense, Streaming SSR)
Its industrial ecosystem (Next.js, TypeScript, Query, Zustand)

Recurring challenges (performance, technical debt, standardization) are largely mitigated through this checklist’s best practices.

In 2025, React remains the universal foundation of modern web development.