CI/CD

A linter is a static analysis tool that automatically scans source code for syntax errors, style violations, potential bugs, and anti-patterns without executing the code. Popular linters include ESLint for JavaScript/TypeScript, Pylint for Python, and Stylelint for CSS. Linters are typically integrated into CI pipelines and editor plugins, enforcing consistent code quality across a team with zero manual effort.

Idempotency means that performing the same operation multiple times produces the same result as performing it once. This property is critical in automation and distributed systems where network failures or retries may cause a request to be sent more than once. APIs, payment processing, and deployment scripts should be designed to be idempotent so that retries are safe and don't create duplicate side effects.

Infinite scroll is a UX pattern where new content loads automatically as the user scrolls toward the bottom of the page, eliminating traditional pagination. It's commonly used in social media feeds and content discovery interfaces. While it increases engagement and feels seamless, it can hurt performance without virtualization and makes it difficult for users to reach footer content or bookmark specific positions.

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.

React Hooks are functions (like `useState`, `useEffect`, `useMemo`, `useCallback`) that let you use state, side effects, and other React features inside functional components without writing classes. Introduced in React 16.8, they fundamentally changed how React applications are structured by enabling logic reuse through custom hooks. Hooks must follow two rules: they can only be called at the top level of a component, and only inside React function components or other hooks.

CSS Animation uses `@keyframes` rules and the `animation` property to create complex, multi-step animations entirely in CSS without JavaScript. Combined with CSS transitions for simple state changes, these tools handle most UI animation needs performantly since browsers can optimize them on the GPU compositor thread. Properties like `transform` and `opacity` are particularly efficient to animate because they don't trigger layout recalculations or repaints.