We will use the web developer tools to look at the network transfers. When we start the application, we get the home page and just a few transfers, including bundle.js, the main source block. This is the file that will grow heavily in size as your application becomes larger. See the following screenshot:
If we click on a link, the corresponding chunk of split code will be transferred. After accessing several of the links, you'd get something like the following:
Even if our example is really tiny, you can see that you could easily partition the application to work in several smaller chunks. We can give no rules to suggest when you should start applying this technique, but, as we've seen, changing any component into an asynchronously loaded equivalent takes little effort, so you could start using the technique, even with all of your application already written.