How can you split code to improve a web application's performance?

To improve a web application's performance, split code into smaller modules, lazy load non-essential parts, and use code splitting techniques like dynamic imports. Splitting CSS and JavaScript files, caching data, and optimizing images can also enhance performance.

Sooner or later every front-end developer finds out that code splitting is crucial for modern SPAs where a big part of the business logic is driven by JavaScript on the client side. As your project grows, so does the amount of JavaScript code. Adding more 3rd party libraries contributes even more for the size of your bundle.

Code splitting is a way to make web apps work better by breaking down the code into smaller pieces. These smaller pieces can then be loaded separately as needed. This means that only the code that is actually being used is loaded, which makes the app load faster. By using code splitting, developers can make apps load smoother and improve the experience for users.

Code splitting is a technique used in software development to optimize the loading performance of web applications by breaking the codebase into smaller, more manageable parts. Instead of loading the entire application code at once, code splitting enables loading only the necessary code for a particular page or feature when it's needed. This helps reduce the initial loading time of the application, improving the overall user experience. Code splitting can be achieved through various methods, such as dynamic imports in JavaScript or using build tools like Webpack, which automatically split the code into separate bundles based on predefined criteria.

To improve a web application's performance, split code by bundling, lazy loading, code splitting, server-side rendering, caching, minification/compression, optimized images, database optimization, CDN usage, and performance monitoring.

Using code bundlers like Webpack, ESBuild or Bun can help with code splitting but they don't work on their own. You have to write your application in certain way to benefit from this ability of the bundlers. Make sure you split your code logically in units - classes, functions, constants, etc. Export them separately as ES modules, even in separate files where it makes sense (for example - Classes). If you use a Front-end framework, follow their best practices in that regard, they definitely have them documented. Each of the modern JS frameworks embraces this coding approach and makes it possible to split and lazy load code.

To implement code splitting, utilize features like dynamic imports() in JavaScript or configure code splitting plugins in build tools like Webpack. Identify parts of the application that can be split into separate bundles and use dynamic imports to load modules or dependencies asynchronously when needed. Additionally, for web applications with multiple routes, implement route-based code splitting by lazy loading route components. Test the implementation to ensure functionality and monitor performance using tools like Chrome DevTools for optimization opportunities. Overall, code splitting optimizes loading performance, reduces initial bundle sizes, and enhances the user experience by loading only necessary code when required.

We can split code by following ways: - Modularization: Break large code chunks into smaller manageable modules for better organization and maintenance - Minification: Remove unnecessary characters like comments, spaces, and line breaks to reduce file size, enhancing load time. - Code splitting: Divide code into smaller bundles, loading only what's needed for each page, reducing initial load time. - Lazy loading: Load non-essential resources, such as images or scripts, asynchronously after the main content to speed up the initial page load. - Caching: Utilize browser caching mechanisms to store frequently accessed data locally, reducing server request and improving response time. - Optimize libraries: Use lightweight libraries and frameworks

Performance Optimization: Reduces initial loading time by splitting code into smaller, more manageable chunks. Improved User Experience: Users experience faster page loads, enhancing overall satisfaction. Efficient Resource Utilization: Allows loading only necessary code for each page, minimizing unnecessary downloads. Enhanced Scalability: Facilitates easier scaling of applications as modules can be loaded dynamically based on demand. Better Maintenance: Simplifies code maintenance by isolating and managing individual modules. Example: Splitting a large e-commerce application into separate bundles for product listing, cart management, and checkout processes.

Code splitting makes tree shaking and lazy loading possible which on its turn helps optimizing the initial load of your app, but also loading of any subsequent modules. This should also be one of the main criteria for choosing 3rd party libraries - they need to have proper code splitting too. This means that only modules that you actually import and use end up in your build.

Code splitting offers numerous benefits for web development, including improved loading performance by reducing initial bundle sizes and speeding up page loading times, resulting in a smoother user experience and higher engagement. It optimizes resource usage by loading only necessary code asynchronously, leading to better scalability and resource efficiency. Additionally, it enhances performance on low-end devices and slow internet connections, making applications more accessible to a wider range of users. Moreover, code splitting improves scalability and maintainability by breaking the codebase into smaller, more manageable chunks, facilitating independent development and easier maintenance over time.

I'd point two main (from my point of view) challenges: 1. Load Balancing: Achieving the right balance between the number of chunks and their sizes is crucial. Too many small chunks can lead to excessive HTTP requests, while too few large chunks might negate the benefits of code splitting. Finding the optimal balance requires careful tuning and testing. So splitting for the sake of it not only adds complexity, but can impact performance negatively. 2. Dependency Management: Managing dependencies between chunks adds complexity. Developers must ensure that shared dependencies are not duplicated across chunks, which increases the overall size of the app and affects load times. Good communication and code base management are crucial.

Maybe one of the greatest challenges is planning the architecture of a new app with code splitting in mind. To be able to do this properly you need to have very clear requirements for the project and good understanding of the technologies that will be used. Refactoring an existing project which is not written with code splitting in mind but is already big is also challenging and time consuming task.

While code splitting offers significant benefits, it also presents some challenges: 1. **Complexity**: Implementing code splitting can introduce complexity to the development process, especially when dealing with dynamic imports, asynchronous loading, and managing dependencies. This complexity may require additional time and effort from developers to ensure proper implementation and maintenance. 2. **Dependency Management**: Splitting code into separate bundles can lead to issues with managing dependencies and ensuring that all necessary modules are loaded when needed. Developers must carefully manage dependencies to avoid missing or conflicting modules, which can impact the functionality.

Divis?o de código sem dúvida é uma prática que qualquer time de desenvolvimento deverá adotar na medida que a solu??o crece. Na minha opini?o é muito importante a maturidade do time para que a ado??o seja bem-sucedida, a complexidade da técnica, dependencias, aumento de número de componentes pode gerar dificultades em times menos expertos.

Measuring can be done for 2 main criteria - size and time. Both usually go together because a smaller file size means less time to load. Use the help of tools like Lighthouse from the Chromium dev tools - it will analyze your page load and show you your weak spots where improvement is needed. It also explains very well what to do in order to improve them which can be very helpful.

Don't forget to aim for consistent performance of your app. The point is not to trick your way into having a 90+ score on your home page for Google's web vitals, your entire app needs to perform well.

1. **Code Splitting**: Divide the application into smaller modules loaded asynchronously. 2. **Bundle Optimization**: Minify and bundle JavaScript and CSS files to reduce size. 3. **Lazy Loading**: Load non-essential resources only when needed. 4. **Caching**: Implement caching mechanisms to store frequently accessed data. 5. **Server-Side Rendering (SSR)**: Generate initial HTML content on the server. 6. **Optimized Images**: Compress and optimize images for faster loading. 7. **Database Optimization**: Optimize queries, index data, and use caching. 8. **Content Delivery Network (CDN)**: Distribute static assets across servers globally. 9. **Load Balancing**: Distribute traffic across multiple servers to prevent overload.

Duas coisas muito importantes: - documenta??o e comunica??o para nivelar o conhecimento entre todos os integrantes do time. - ter alguns expertos no time e treinar aos devs nas ferramentas e no processo.