Lighthouse score: from 60 to 90, how many hairs did I lose?

To improve a Lighthouse score from 60 to 90, focus on optimizing performance, accessibility, SEO, and best practices. For performance, prioritize resolving resource loading and render-blocking issues, such as lazy loading images and on-demand JavaScript loading. Accessibility improvements include proper use of ARIA attributes and adjusting color contrast. SEO enhancements involve semantic tags and structured data. Best practices focus on security policies and modern API usage. Debugging tools like Chrome DevTools help analyze issues in depth. Continuous monitoring with automation tools ensures sustained optimization. The article also shares solutions for tricky problems like layout shifts caused by font loading and Service Worker caching strategies.

"First screen loading slows down by 0.5s, user retention drops by 20%"—front-end performance anxiety

Front-end performance optimization directly impacts user experience and commercial value. A 0.5-second delay in first-screen loading may lead to a 20% user loss. The core of performance issues lies in the博弈 between user wait time and psychological expectations. Research shows that 53% of users will leave if page loading exceeds 3 seconds. Key metrics such as FCP and LCP measure content rendering time. While modern frameworks improve efficiency, they introduce additional overhead, requiring attention to unnecessary re-renders. Resource loading strategies include preloading critical resources and image optimization. JavaScript execution optimization involves code splitting, lazy loading, and WebWorker usage. CSS performance optimization requires avoiding layout thrashing and reducing re-computation. Build tools like Webpack can enhance performance through reasonable configuration. Continuous monitoring is achieved using the Performance API and RUM. Browser新特性 like the ContentVisibility API offer performance potential. Mobile端 considerations include touch delay and memory management. Performance optimization must balance accessibility. Organizational practices should establish performance budgets, build a performance culture, and incorporate metrics into KPI assessments.

Mobile adaptation: Why does my page look different on iPhone and Android?

Mobile adaptation is a critical issue in front-end development. Differences in screen size, resolution, browser engines, and system features between iPhone and Android devices can cause the same code to render differently across devices. In terms of screen size and resolution, iPhones and Androids have different logical pixel widths, requiring viewport configuration for adaptation. High DPR (device pixel ratio) on certain devices may lead to blurry images, necessitating targeted optimization. Browser engine differences result in CSS compatibility issues, such as the need for prefixes with flexbox. System fonts and default styles vary, requiring default style resets. Touch event handling mechanisms differ—for example, iOS's elastic scrolling requires special treatment. For unit selection, it's recommended to use relative units like rem or vw/vh. Safe areas must be adapted for notched and punch-hole screens. Button heights differ between iOS and Android, requiring uniform height adjustments. Dynamic adaptation solutions can involve JavaScript to detect device types and apply targeted style adjustments. For testing and debugging, tools like Chrome DevTools, Safari's responsive design mode, Android Studio emulators, and real-device testing are recommended.

Is Safari the new IE?

Safari, as Apple's default browser, has significant compatibility issues. Front-end developers frequently encounter problems such as delayed support for CSS features and JavaScript APIs. For example, the `:has()` selector was not supported until iOS 15.4, IndexedDB has memory leaks, WebRTC functionality is incomplete, and WebComponents support was delayed. The WebKit engine exhibits unique behaviors in Flexbox and Grid layouts, such as late support for the `gap` property compared to other browsers. Safari's debugging tools are limited, requiring macOS for remote debugging, and ServiceWorker debugging is challenging. Its update mechanism is tied to the system, leading to users staying on outdated versions for extended periods. Apple's closed ecosystem restricts PWA development, with many features like push notifications and full-screen experiences missing. Developers must adopt progressive enhancement and feature detection strategies. The community's attitude toward Safari has shifted, with some projects dropping support for older versions. Although the WebKit team has accelerated implementation of new standards, fundamental issues remain unresolved.

"This feature is supported in Chrome, but what about IE?" — the destructive power of compatibility issues

Browser compatibility issues primarily stem from differences in how different vendors implement web standards. Chrome and IE have significant differences in rendering engines, JavaScript engines, and CSS support, leading to inconsistent front-end performance. Code examples show that modern JavaScript methods may not work in older versions of IE and require additional handling. CSS3 features like Flexbox and gradient backgrounds need special prefixes or alternative implementations in IE. Event handling and HTML5 features such as Canvas have varying levels of support across browsers. Performance optimization techniques may yield opposite results in different browsers. Solutions include feature detection, polyfills, build tools for automatic prefixing, and differentiated output. Large projects often adopt unified foundational libraries and automated testing. Mobile devices introduce new compatibility challenges, such as touch events and high-resolution screen adaptation. Even as IE phases out, ongoing evolution in standards continues to present new challenges.

"CI/CD: One deployment, three days of debugging."

In modern frontend development, CI/CD has become a standard, but its practical implementation often faces various challenges. The deployment process may take only minutes, but subsequent debugging can consume hours. Automated workflows may appear flawless yet hide numerous pitfalls. Misconfigured environment variables can lead to production failures, while dependency issues—particularly breaking changes in indirect dependencies—can render rollbacks ineffective. High test coverage often overlooks edge cases, creating a false sense of security. Discrepancies between environments, such as polyfills or API configurations differing between local development and production, can trigger hidden issues. Monitoring gaps, like uncaught Promise rejections or device-specific compatibility problems, persist. Dependency management is complex, with `npm audit` potentially introducing new risks. Multi-layered caching mechanisms may trap users in outdated versions. Infrastructure-as-code misconfigurations can erupt during traffic spikes. Micro-frontend architectures complicate version management and style isolation. Long-tail issues, such as browser-specific bugs, are hard to diagnose. TypeScript's type safety can break at runtime. Human errors, like accidental database deletions, remain a threat. These real-world challenges demand vigilance and the establishment of more robust defense mechanisms.

The more sophisticated the toolchain (Babel, ESLint, Prettier), the fewer the hairs left.

In modern frontend development, the combination of Babel, ESLint, and Prettier significantly enhances efficiency but also introduces configuration complexity. Babel handles code compatibility transformation but faces challenges with polyfill confusion and configuration conflicts. ESLint, as the code quality gatekeeper, often encounters issues with rule priority conflicts and TypeScript integration. Prettier enforces consistent formatting but requires compromises with ESLint rules. When these tools collaborate, execution order and performance overhead become hidden costs. Over-pursuing a perfect toolchain may lead to configuration bloat and a steep learning curve. It is recommended to introduce tools as needed, unify team configurations, and leverage automated workflows to balance efficiency and maintenance costs.

Webpack vs Vite vs Rollup: A configuration engineer's nightmare

Modern front-end build tools like Webpack, Vite, and Rollup each have distinct characteristics but come with complex configurations. Webpack, as a comprehensive tool, requires handling various resource loading and environment setups. Vite offers fast startup but still needs fine-tuning for compatibility and SSR. Rollup is well-suited for library development but imposes strict requirements on module formats and external dependencies. The article presents optimization methods such as configuration layering, type safety, validation, and visualization, while also highlighting breaking changes between versions and performance tuning techniques. Finally, it addresses potential configuration conflicts and solutions when mixing these tools.

TypeScript: A Savior or a New Hair-Loss Culprit?

TypeScript, as a superset of JavaScript, has rapidly risen in front-end development. Its core advantage lies in its static type system, which can catch type errors early and provide powerful code hints and refactoring capabilities, making it particularly suitable for maintaining large-scale projects. However, it also introduces challenges such as a steep learning curve and complex configuration. Advanced features like type gymnastics, while powerful, may increase code comprehension difficulty. TypeScript supports incremental migration, allowing existing JavaScript projects to gradually introduce type checking. Modern build tools now fully support TypeScript, and in team collaboration, type definitions serve as an important form of documentation, though their maintenance can spark debates. As TC39 proposals advance, some features are being incorporated into the JavaScript standard. The TypeScript team is also continuously optimizing performance, with future versions set to further improve compilation speed and reduce memory usage.

AR and WebXR: "Drinking" Virtual Coffee in the Browser

WebXR technology enables augmented reality experiences like virtual coffee drinking through browsers, with core components including WebXR API fundamentals and detection methods. Building the scene requires 3D model loading, plane detection, and interaction systems. Three.js is used to load GLTF-format coffee cup models, while the WebXR plane detection API allows virtual objects to interact with real surfaces. Gyroscope detection and physical feedback are added to simulate drinking effects. Performance optimization involves model simplification, texture compression, and lazy loading. Cross-browser compatibility solutions include fallback 2D/3D scenes. AR interface design should consider information layering and spatial arrangement. Future possibilities include integrating gesture recognition, multi-user sharing, and AI interaction. Practical deployment recommendations emphasize progressive enhancement, performance monitoring, and user guidance.