Did you know that the average website takes over 16 seconds to load on a mobile device? Did you know that on average the amount JavaScript and CSS that goes wasted is over 60%! If JavaScript and CSS are our most expensive resources to load, why are we hurting our load times by shipping stuff we don't ever use? How do we get rid of this unused code? How can we profile our web applications load times? 

Join me as I teach you about the performance constrains of the modern Web, and how to write rich applications within these boundaries using household tools like webpack.

 We’ll learn about how webpack solves these performance problems through a concept called code-splitting. We will walk through examples of code-splitting together, the many ways you can leverage it in your web application, and how webpack  enhances this feature using magic comments, service workers, and prefetch and preload!

By the end of this talk you know:

1. Where the most costly resources in your we application
2. How to profile and analyze a web application load-times
3. Understand what is "unused code" and how to get rid of it with code-splitting and webpack
4. Learn the many types of code splitting in webpack, and other performance related features like service worker and how to integrate them with webpack
5. Learn how frameworks adopt code-splitting and the route, component, and library level
6. How to implement this in your own codebase

参考翻译：

你是否知道，网站在移动设备上的平均加载时间超过16秒？
你是否知道，加载的JavaScript和CSS资源平均浪费超过60%？
如果JavaScript和CSS是我们要加载的最昂贵的资源，那为什么要浪费时间去加载一些根本用不着的东西？
我们如何去掉未使用的代码？我们应该如何剖析Web应用的加载时间？

本次演讲将介绍现代Web的性能约束，并讲解如何使用像webpack这样的工具在约束之下编写内容丰富的应用。

我们将学习webpack如何通过一个叫代码分离（code-splitting）的概念来解决这些性能问题。我们将通过一些例子来学习，这里演示的方法都可以直接用在自己的Web应用中。我还将分享webpack如何使用魔法注释（magic comment）、service worker、预取（prefetch）和预加载（preload）等特性来增强代码分离。

你将学到：
1.如何定位Web应用中最昂贵的资源
2.如何分析Web应用的加载时间
3.理解哪些是未使用代码，以及如何通过代码分离与webpack去掉它们
4.学习webpack中不同类型的代码分离，了解像service worker等其他性能相关的特性，以及如何将其与webpack集成