Quelles sont les meilleures pratiques de performance Web pour les applications monopage React et Angular ?

In Angular, there are a lot of options to improve performance. Depending on what exactly you want to optimize, you can consider the following options: 1. Bundle Size: using modern Standalone API because it is more tree-shakeable, using lazy loading in Angular router, using deferred views. 2. Runtime: use pure pipes, use memoize techniques for methods with heavy computations. For thread-blocking operations use WebWorkers. Enable onPush change Detection strategy. Use new reactive primitives called “signals” and the new control flow syntax. Those are just a few of the tips.

These techniques are crucial for improving initial load times and user experience by only loading what's needed and when needed. Another aspect worth considering is the efficient use of caching strategies and service workers to enhance performance further. By caching assets and leveraging service workers, applications can reduce load times on subsequent visits, making the user experience smoother. Integrating these with code splitting and lazy loading can significantly boost SPA performance.

For React and Angular single-page applications (SPAs), key performance practices include lazy loading components and routes, optimizing bundle size through code splitting, minimizing render cycles with PureComponent and ChangeDetectionStrategy.OnPush, leveraging virtualization for large lists, caching data and API responses, implementing server-side rendering (SSR) or static site generation (SSG), and using performance monitoring tools for continuous optimization.

In addition to these points about performance, one thing we need to keep in mind is using all the resources we have in our framework. In React for example, there are many hooks provided by the framework specifically for performance, such as "useCallback", "memo", "useMemo"and others. They can provide a way to improve even more your application.

Code splitting and lazy loading are essential techniques for optimizing the performance of single-page applications (SPAs) built with React and Angular. Here are some key points: 🌐 Code Splitting: 🔸 Reduced Load Time: ➢ Breaks down the app into smaller chunks for faster initial loading. 🔸 Improved UX: ➢ Enhances user experience with quicker page loads, crucial for slower connections. 🔸 Optimized Bandwidth: ➢ Reduces data transfer, optimizing bandwidth usage for improved performance. 🌐 Lazy Loading: 🔸 On-Demand Loading: ➢ Loads modules/components only when required, reducing initial payload. 🔸 Improved Performance: ➢ Avoids unnecessary code loading for faster page rendering and improved performance.

In Frameworks like Next.js, we can use Server-side rendering patterns like SSG, ISR, On-Demand SR, SSR, and Streaming Server Components, we can distribute the rendering tasks to the server and client by using client/server components combined with the mentioned patterns and benefit from lower FCP, TTI TTFB, TBT resulting in significant better performance of the pages. We need to keep in mind that everything even client components will be at least rendered on the server time once and will be hydrated to the client to attach event handlers and browser-only APIs. So we need to keep track of the server workload and optimize the balance to not overload the servers with unnecessary processes.

Server-side rendering and pre-rendering allow for faster page loads and result in better SEO. In this approach, the server is responsible for rendering part or the entirety of the page, serving clients with ready-to-go pages. Due to the low costs of cloud resources, server-side rendering and pre-rendering have made a comeback in recent years.

Server-Side Rendering and Pre-Rendering: Consider server-side rendering (SSR) for faster initial content rendering and improved SEO. Explore static site generation (SSG) to generate static HTML pages at build time for faster loading.

Server-side rendering (SSR) and pre-rendering add complexity to the development process and can increase server load and latency. They also require handling both client-side and server-side code, which can introduce maintenance challenges. Additionally, SSR does not inherently support easy caching, which can impact performance for high-traffic sites.

Implementar uma estrutura de renderização do lado do servidor, com frameworks como o Next.js ou até mesmo React Vanilla, é essencial para aplicações como e-commerce e blogs, permitindo que buscadores encontrem facilmente páginas de produtos e notícias. Além disso, também otimiza o uso de memória e processamento dos aparelhos de usuários que acessam o site, trazendo a pré-renderização das páginas para o servidor, e melhorando métricas de webvitals, principalmente em aparelhos móveis.

Optimizing images and fonts can introduce additional complexity and time to the development process. It may require developers to learn and implement various tools and techniques, which can be time-consuming. Additionally, achieving the right balance between quality and performance might require multiple iterations and testing, potentially delaying the project timeline. Finally, using modern formats and optimization tools might lead to compatibility issues with older browsers or devices that do not support them.

1. Compress and resize images to reduce file size without sacrificing quality. 2. Use modern image formats like WebP for better compression. 3. Lazy load images to prioritize loading visible content first. 4. Minimize the use of custom fonts, and if necessary, optimize font loading using font-display property.

Optimizing images and fonts is essential for enhancing the performance of web applications. For images, it's crucial to choose the right format based on the content and purpose, such as using JPEG for photographs and PNG for images with transparency. Compressing images using tools like ImageOptim or TinyPNG reduces file sizes without compromising quality. For fonts, subsetting only including necessary characters, reduces file sizes, while using the WOFF2 format and asynchronous loading enhances font delivery.

To optimize images and fonts for your SPA's performance: ✔️Use responsive images with <picture> or srcset/sizes for different devices. ✔️Opt for modern formats like WebP, AVIF, or JPEG ✔️Compress images using tools like ImageOptim or TinyPNG. ✔️Subset fonts with tools like Font Squirrel to reduce file size. ✔️ Control font rendering with the font-display property ....

Use the <picture> element or the srcset and sizes attributes to serve the most suitable image size for different devices and resolutions. This ensures that users receive an appropriately sized image based on their device's capabilities, reducing unnecessary data transfer and improving rendering performance. In my experience, I always utilise modern image formats like WebP, AVIF, or JPEG 2000, which offer better compression and quality compared to traditional formats like JPEG or PNG.

⟡ Utilize caching mechanisms to store static assets like CSS, JavaScript, and images, reducing server requests and enhancing load times ⟡ Implement service workers to enable offline functionality, allowing the app to work even when the user is offline by caching essential assets ⟡ Utilize tools like Workbox for easier service worker implementation and management ⟡ Employ techniques like lazy loading to defer loading non-critical resources until needed, optimizing initial load times ⟡ Employ efficient bundling and code-splitting strategies to minimize bundle size and prioritize critical code for faster rendering

I have used in-memory cache as well as leveraged Aerospike and Redis to cache HTML to serve the users really quick. We maintained versions of the HTML based on certain attributes like (A/B experiments, user preferred language, country etc). Using caching technique is a great way to improve FCP for a page which greatly contributes to web performance.

Implementing efficient cache expiration policies ensures that stale resources are regularly purged from the cache, maintaining the integrity and freshness of your application’s content. Leveraging service worker strategies like push notifications and background sync can enhance user engagement and provide seamless experiences, even in challenging network conditions. Conducting regular performance audits and monitoring the effectiveness of caching and service worker implementations through tools like Lighthouse or Google Chrome DevTools can help identify areas for further optimisation and refinement. Regular performance audits and caching & service workers help to improve reliability, particularly in offline situations.

✔️ To optimize the performance and reliability of your SPA, especially in offline or low-network scenarios, leverage caching and service workers. Caching involves storing web resources like images, scripts, or stylesheets in the browser's cache or a custom cache, allowing for reuse without fetching from the server. Service workers are background scripts intercepting network requests, enabling control over resource caching and serving. React and Angular offer tools like Create React App, Workbox, Angular PWA, and Ngsw-config for implementing caching and service workers. ✔️Employing in-memory cache and technologies like Aerospike and Redis to cache HTML can significantly improve page load times.

Leveraging caching and service workers can significantly enhance the performance and reliability of your single-page application (SPA), particularly in offline or low-network scenarios. Here's how you can effectively utilize these strategies: Caching: Store frequently accessed web resources such as images, scripts, or stylesheets in the browser's cache or a custom cache. This allows these resources to be reused without fetching them from the server, thereby reducing load times and improving performance. Implement caching strategies such as browser caching, where resources are stored locally by the browser, or application-level caching, where resources are stored in a custom cache managed by your SPA.

1. Use tools like Google Lighthouse, WebPageTest, or browser developer tools to analyze performance metrics. 2. Monitor metrics such as Time to First Byte (TTFB), First Contentful Paint (FCP), and Time to Interactive (TTI). 3. Regularly track performance over time to identify any regressions and continuously optimize your application.

Optimizing React and Angular SPAs involves code splitting to load only necessary components, minification and compression for smaller files, lazy loading to defer loading non-essential resources, SSR or pre-rendering for faster initial page loads, image optimization, virtualizing long lists, memoization, and pure components to reduce re-renders, performance monitoring to identify bottlenecks, and optimized bundling with tree shaking to eliminate dead code. These practices collectively enhance user experience and page load times.

Monitoring and measuring performance is crucial for React and Angular SPAs. Integrate performance budgets into CI/CD to maintain standards. Leverage Real User Monitoring (RUM) to capture real-world user experiences influenced by device, network, and interactions. Employ custom performance markers using Angular's `markForCheck()` or React's Profiler API to measure rendering times, aligning insights with SPA frameworks. Test under various network conditions, considering service workers and caching strategies. Regularly employing standard and cutting-edge monitoring tools ensures SPAs remain efficient, responsive, and robust across user scenarios, enhancing user experience and aligning with modern practices.

Google's Lighthouse is your greatest friend for measuring web performance. Another notable thing which I have done in the past is used Lighthouse APIs to generate scores daily and plot them on graphs which helped us analyse the web performance overtime, and also make sure that the score doesn't dip after any release.

Monitoring and measuring performance is critical for both React and Angular SPAs. In React, tools like Chrome DevTools and Lighthouse analyze metrics such as First Contentful Paint (FCP) and Time to Interactive (TTI), helping developers optimize code and caching strategies for responsive applications. Similarly, in Angular, monitoring tools such as Angular CLI's performance tools and Lighthouse audits track metrics like Time to First Byte (TTFB) and network performance, enabling developers to enhance application speed and reliability across diverse environments. These practices ensure efficient, high-performance SPAs that deliver an optimal user experience.

When it comes to using React and Angular there is one thing that many people are forgetting. Use Vue instead. Then you won't have all the issues from React and Angular; you will have a completely new set of issues to work through. You're welcome.

there can be other ways by we can optimize our react project 1.Minimizing re-rendering which can be acheived by using hooks like useCallback and useMemo 2.Tree shaking can be useful also as it will remove the unused code 3.CDN,preloading ,prefetching 4.using webpack for optimize bundled size

- Code Splitting - Lazy Loading - Minification and Compression - Image Optimization - Server-Side Rendering (SSR) - CDN Usage - Caching Strategies - Bundle Analysis - Debouncing and Throttling - Performance Monitoring

In addition to the aforementioned strategies, it’s crucial to cultivate a culture of continuous improvement within your development team. Encouraging regular discussions and knowledge sharing sessions on web performance best practices can empower team members to contribute ideas and solutions. Staying updated on the latest developments in web technologies and performance optimization techniques through industry conferences, online courses, and community forums fosters innovation and keeps your SPA at the forefront of performance excellence. Optimising web performance is an ongoing journey, and by fostering a collaborative and proactive environment, you can continuously enhance the user experience and stay ahead of the competition.

✔️ Incorporating caching and service workers into your SPA can greatly enhance its performance and reliability, particularly in offline or low-network environments. Utilize caching to store frequently used web resources in the browser's cache or a custom cache, and implement service workers to control caching and resource serving. Leverage tools like Create React App, Workbox, Angular PWA, or Ngsw-config for efficient implementation. ✔️Consider utilizing in-memory cache and advanced technologies like Aerospike or Redis to cache HTML, tailoring versions based on user attributes for a personalized experience.