Focus Management

A component library is a curated set of pre-built, reusable UI elements — buttons, inputs, modals, cards — packaged for consistent use across projects. Libraries like Material UI, Chakra UI, or Radix provide accessible, themeable building blocks so developers don't have to reinvent common patterns. A well-maintained component library drastically reduces development time and ensures visual consistency throughout an application.

The View Transitions API is a browser-native way to create animated transitions between different DOM states or page navigations, previously only possible with complex JavaScript animation libraries. It captures a snapshot of the current state, applies the DOM update, then animates between the old and new snapshots using CSS. This API works for both single-page app state changes and multi-page navigations, enabling smooth page transitions with minimal code that feels native to the platform.

Server-Side Rendering (SSR) is a technique where web pages are rendered to HTML on the server for each request, rather than relying on client-side JavaScript to build the page in the browser. SSR provides faster initial page loads and better SEO since search engines receive complete HTML content. Modern SSR in frameworks like Next.js supports streaming, allowing the server to progressively send HTML chunks as they become ready rather than waiting for the entire page to render.

Deep linking is the ability to direct users to a specific screen or content within a mobile or web application via a URL, rather than just opening the app's home screen. In React Native and Flutter, this involves configuring URL schemes (e.g., `myapp://profile/123`) or universal/app links that work across platforms. Deep linking is essential for push notification routing, marketing campaigns, sharing content between users, and creating seamless web-to-app transitions.

A design system is a collection of reusable components, guidelines, and standards that ensure visual and functional consistency across a product or suite of products. It typically includes a component library, design tokens, typography rules, color palettes, and documentation. Design systems bridge the gap between designers and developers, enabling teams to build interfaces faster while maintaining a unified look and feel.

Memoization in React is a performance optimization that caches the result of expensive computations or component renders to avoid redundant work on re-renders. React provides `React.memo()` to skip re-rendering a component when its props haven't changed, `useMemo()` to cache computed values, and `useCallback()` to cache function references. While powerful, premature memoization adds complexity — it's best applied after profiling confirms an actual performance bottleneck.