 Microsites are fast because they're typically small, lightweight, and static. I'm Tom, and today I'm going to show you how you can use a microsoft to speed up loading of your PWA. Microsites are small mini websites that typically serve to inform about one particular topic, and are separate from a brand's regular web app or even progressive web app. While regular web apps can be pretty heavy because they are, well, fully dynamic apps like e-commerce or comparison sites, microsites typically are super lightweight and mostly static, and often have their own easy-to-remember domain names or subdomains. Frequently, microsites are advertised on TV or in online advertising campaigns. They go, engage the user to click through to the app. I've built a little microsoft for AffiliCats, the comparison site that compares offers for cats, which I featured regularly in the series. Other than the full dynamic AffiliCats app that shows many cats, compares surprises, shows their details and reviews, etc. The microsoft really just advertises one concrete cat and is therefore lightning fast to load. But how do we bridge the gap from a lightweight microsoft to a fully dynamic progressive web app? The AffiliCats microsoft has a hidden superpower. It uses service workers and their ability to pre-cash content. Let's search for the microsoft on Google, maybe because we've heard about it in an ad on TV. The microsoft is the number one result, so let's click through. As expected, it opens lightning fast, but in the background something cool has happened. When we were looking at the microsoft, behind the scenes, the service worker for the AffiliCats progressive web app was installed. In its install event, it pre-caches the key resources it needs to ensure the PWA starts lightning fast. So when we then click through to the AffiliCats progressive web app, everything needed can come directly from the cache, instead of having to go to the network. So how does this work? The secret is an invisible and empty IFrame on the microsite that is hosted on the origin of the PWA. The only thing this IFrame does is install the service worker, so that when we click through, the resources needed are already in the cache. So we do not only start fast, we also stay fast. This trick is also possible with AMP, Accelerated Mobile Pages, using a neat web component called AMP install service worker. I've implemented a microsite in AMP as well, so if you're interested in AMP, you can also check out the AMP approach. Both examples are available on my GitHub page. And with that, start fast and stay fast. Why do you want to build progressive web apps? Share your thoughts in the comments and let me know what else you want me to cover in potential future episodes. Thanks for watching.