 All right. Welcome back to Chrome Dev Summit 2016 everyone. I finally was able to track down Alex Russell after giving an amazing presentation yesterday We're here backstage kind of winding down the day But I did want to ask Alex a few questions about his his talk on progressive web apps yesterday So it's about building really fast progressive web apps. Is that right? Yeah, I sort of spent some time going through the real-world constraints of mobile devices because the way mobile phones work is actually very different in terms of the Capacity and capabilities CPU disk network, they're all fundamentally different than the what we're used to on desktop So what do you think about like the dev tools emulation like is that enough to test just as a developer like I go in there I use the tools, but I should be actually testing on real devices. Yeah Dev tools is getting a lot better about its fidelity with mobile. So for instance, you've had the network Throttling in DevTools for a while, but we're adding CPU throttling now and that gets you closer still But JavaScript execution on a phone is often ten times slower than it is on desktop And if you aren't testing on a real device on a real network on a representative network It's easy to miss the things that can really destroy the Performance of the experience that you're trying to deliver. I know there's other things like like script parsing performance Like all these things add up over time. Sam Scone. He had a really awesome presentation on that as well Well, I have you here I do want to talk about service worker since you're one of the you know the spec authors of service worker You've been working on it a long time There's a lot of great stuff in that in that API surface area What's kind of coming in the next couple of months that gets you really excited about things that are changing? Yeah, two things I'm extraordinarily excited about streams Watch Jake's talk catches blog posts streams are transformative for the performance of mobile applications when you're using service workers and Something that we're calling navigation preload basically the ability to Not wait on the service worker to start up before we go to the network for content potentially So this is going to speed up a bunch of the biggest sites on the web that are using service workers today Awesome, so your service workers going to get that much faster streams going to make everything better We'll definitely hit up Jake for some questions on that later. All right guys We're going to sign off for now. Please join us on YouTube and hashtag chrome devs summit on Twitter. Thanks a lot