Dart

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.

Infrastructure as Code (IaC) is the practice of managing and provisioning servers, networks, and cloud resources through machine-readable configuration files rather than manual processes. It enables version control, code review, and automated testing of infrastructure changes just like application code. Tools like Terraform, Pulumi, and AWS CloudFormation are popular IaC solutions that make environments reproducible and consistent.

Optimistic UI is a pattern where the interface immediately reflects the expected result of a user action before the server confirms it. For example, a "like" button instantly shows the liked state while the API request happens in the background. This makes the app feel significantly faster and more responsive. If the server request fails, the UI rolls back to the previous state and notifies the user.

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.

Drag and drop is an interaction pattern that lets users move, reorder, or transfer UI elements by clicking (or touching), holding, and dragging them to a new position. It's used for file uploads, kanban boards, sortable lists, and layout builders. The HTML Drag and Drop API provides native browser support, while libraries like dnd-kit and react-beautiful-dnd offer more polished, accessible, and touch-friendly implementations.

Code splitting is an optimization technique that breaks a JavaScript bundle into smaller chunks that are loaded on demand, rather than forcing users to download the entire application upfront. In React, this is achieved through `React.lazy()` and dynamic `import()` statements, which create separate bundles loaded only when the corresponding component or route is accessed. This dramatically improves initial load times, especially for large single-page applications with many routes.