10 Ways to Optimize the Performance of Large-Scale Angular Applications to Improve Time to Interactive (TTI)
Fernando Nunes
Software Engineer | Full Stack Developer | Angular | Nodejs | Nestjs | React | AWS | Azure
Abstract: This article explores ten advanced strategies to optimize the performance of large-scale Angular applications, focusing on improving the Time to Interactive (TTI). The techniques discussed include Lazy Loading, Pre-Rendering and Server-Side Rendering (SSR), Ahead-of-Time (AOT) Compilation, Tree Shaking, Change Detection Optimization, Minification and Uglification, Use of Web Workers, Caching and Service Workers, Asynchronous Resource Loading, and Performance Analysis. Code examples and references are provided to illustrate recommended practices.
Introduction
In modern web application development, performance is a critical factor that directly affects user experience and product success. The Time to Interactive (TTI) is an essential metric that measures the time from when a page starts loading to when it's fully interactive. Optimizing TTI in large-scale Angular applications is crucial to ensure a fast and responsive user experience.
This article presents ten effective strategies to significantly improve TTI in Angular applications, providing detailed explanations, practical contexts, and code examples for each technique.
Optimization Strategies
1. Lazy Loading
Description:
Lazy Loading allows modules to be loaded on demand, reducing the initial bundle size and improving TTI. This is especially beneficial in large-scale applications with many modules.
Implementation Example:
// app-routing.module.ts
import { NgModule } from '@angular/core';
import { Routes, RouterModule } from '@angular/router';
const routes: Routes = [
{
path: 'feature',
loadChildren: () => import('./feature/feature.module').then(m => m.FeatureModule)
},
// other routes
];
@NgModule({
imports: [RouterModule.forRoot(routes)],
exports: [RouterModule]
})
export class AppRoutingModule { }
Benefits:
2. Pre-Rendering and Server-Side Rendering (SSR)
Description:
Pre-rendering and Server-Side Rendering (SSR) use Angular Universal to render the application on the server. This improves TTI by delivering a pre-rendered version of the page to the user and benefits SEO as search engines can easily index the content.
Implementation Example:
Setting Up Angular Universal:
ng add @nguniversal/express-engine
In package.json:
"scripts": {
"build:ssr": "ng build && ng run your-project:server",
"serve:ssr": "node dist/your-project/server/main.js"
}
npm run build:ssr
npm run serve:ssr
Benefits:
3. Ahead-of-Time (AOT) Compilation
Description:
Ahead-of-Time (AOT) Compilation compiles Angular code during the build process instead of in the browser. This reduces the application's bootstrap time, improving TTI and decreasing bundle sizes.
Implementation Example:
Enable AOT in Production Build:
Angular CLI uses AOT by default in production builds.
ng build --prod
Explicit Configuration in angular.json:
"configurations": {
"production": {
"aot": true,
// other options
}
}
Benefits:
4. Tree Shaking
Description:
Tree Shaking is a technique that eliminates dead code during the build process. In Angular, using ES6 modules and tools like webpack allows unused code to be removed, reducing the final bundle size.
Implementation Example:
Module Structure:
// math.helpers.ts
export function add(a: number, b: number): number {
return a + b;
}
export function subtract(a: number, b: number): number {
return a - b;
}
export function multiply(a: number, b: number): number {
return a * b;
}
export function divide(a: number, b: number): number {
return a / b;
}
// app.component.ts
import { Component } from '@angular/core';
import { add } from './math.helpers';
@Component({
selector: 'app-root',
template: <h1>Result: {{ result }}</h1>
})
export class AppComponent {
result = add(5, 3);
}
How It Works:
5. Change Detection Optimization
Description:
Angular uses a change detection mechanism to update the user interface. The default strategy (Default) can cause overhead in complex applications. The OnPush strategy optimizes this process by checking for changes only when component inputs are updated.
Implementation Example:
// optimized.component.ts
import { Component, ChangeDetectionStrategy, Input } from '@angular/core';
@Component({
selector: 'app-optimized',
template: <p>{{ data.name }}</p>,
changeDetection: ChangeDetectionStrategy.OnPush
})
export class OptimizedComponent {
@Input() data: { name: string };
}
Benefits:
6. Minification and Uglification
Description:
These processes reduce the size of JavaScript and CSS files by removing whitespace, comments, and renaming identifiers. This results in faster load times and improves TTI.
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Configuration Example:
In angular.json:
"configurations": {
"production": {
"optimization": {
"scripts": true,
"styles": true,
"fonts": true
},
"outputHashing": "all",
// other options
}
}
How It Works:
Result:
7. Use of Web Workers
Description:
Web Workers allow scripts to run in separate threads, preventing heavy operations from blocking the main thread. This keeps the user interface responsive and improves TTI.
Implementation Example:
Creating a Web Worker:
ng generate web-worker app
Worker Implementation:
// app.worker.ts
/// <reference lib="webworker" />
addEventListener('message', ({ data }) => {
const response = isPrime(data);
postMessage(response);
});
function isPrime(num: number): boolean {
// Function implementation to check if a number is prime
}
Interaction in Angular Component:
Benefits:
8. Caching and Service Workers
Description:
Service Workers allow you to control the browser cache, enabling offline functionality and improving load times on subsequent visits.
Implementation Example:
Installing Service Worker Support:
ng add @angular/pwa --project your-project
Configuring ngsw-config.json:
{
"index": "/index.html",
"assetGroups": [
{
"name": "app",
"installMode": "prefetch",
"resources": {
"files": ["/favicon.ico", "/index.html"],
"versionedFiles": ["/*.bundle.css", "/*.bundle.js"]
}
},
{
"name": "assets",
"installMode": "lazy",
"updateMode": "prefetch",
"resources": {
"files": ["/assets/**"]
}
}
]
}
Registering in the Main Module:
// app.module.ts
import { ServiceWorkerModule } from '@angular/service-worker';
@NgModule({
// ...
imports: [
// ...
ServiceWorkerModule.register('ngsw-worker.js', { enabled: environment.production })
],
// ...
})
export class AppModule { }
Benefits:
9. Asynchronous Resource Loading
Description:
Asynchronous loading of resources like scripts and styles prevents blocking the main thread, allowing the browser to process other page elements simultaneously. This improves TTI by not hindering the initial rendering.
Implementation Example:
Asynchronously Loading External Scripts:
In your index.html:
<script src="https://example.com/some-script.js" async></script>
Asynchronous Loading in Components:
To dynamically load JavaScript modules:
// some.component.ts
@Component({ /* ... */ })
export class SomeComponent implements OnInit {
ngOnInit() {
import('path-to-your-module').then(module => {
// Use the dynamically loaded module
});
}
}
Asynchronously Loading Styles:
In your angular.json, use the lazy option:
"styles": [
{
"input": "src/styles.css",
"lazy": true,
"bundleName": "styles"
}
]
And dynamically load styles in the component:
// app.component.ts
constructor(private domSanitizer: DomSanitizer) {}
loadStyles() {
const linkElement = document.createElement('link');
linkElement.rel = 'stylesheet';
linkElement.href = this.domSanitizer.bypassSecurityTrustResourceUrl('styles.bundle.css') as string;
document.head.appendChild(linkElement);
}
Benefits:
10. Performance Analysis
Description:
Using performance analysis tools helps identify bottlenecks and optimization opportunities. Tools like Lighthouse and Chrome DevTools provide valuable insights on how to improve TTI.
Usage Example:
Using Lighthouse:
Access Lighthouse:
Generate a Report:
Analyze Results:
Using Chrome DevTools:
Monitor Performance:
Identify Bottlenecks:
Benefits:
Conclusion
Optimizing the Time to Interactive (TTI) in large-scale Angular applications is a multifaceted challenge that requires the combined application of various advanced techniques. The ten strategies presented in this article provide a comprehensive guide to significantly improve your application's performance.
As technical leaders and senior developers, it's essential not only to understand these techniques but also to apply them in an integrated and efficient manner. Combining code optimizations, architectural improvements, and infrastructure enhancements will result in a faster, more responsive application capable of delivering an exceptional user experience.
References
Senior Software Engineer | Fullstack Software Developer | Java | Spring Boot | Micro Services | Angular | AWS | TechLead | Head Solutions
5 个月Good points! Tks for sharing with the comunity!
.NET Developer | C# | TDD | Angular | Azure | SQL
5 个月Thanks for sharing!
Fullstack Software Engineer | Node.js | React.js | Javascript & Typescript | Go Developer
5 个月Awesome tips Fernando Nunes. Thanks for sharing.
Senior Ux Designer | Product Designer | UX/UI Designer | UI/UX Designer | Figma | Design System |
5 个月Great read, Fernando Nunes! I particularly appreciated the section on Lazy Loading. By implementing this strategy, we can significantly reduce the initial bundle size and improve the Time to Interactive (TTI). It's amazing how such a simple optimization can make a huge impact on user experience.
Senior Fullstack Software Engineer | Typescript | Node | React | Nextjs | Python| Golang | AWS
5 个月Nice content, thanks for sharing!