Understanding performance is no easy task. There are a lot of conflicting arguments sprinkled throughout the Internet, and it's hard to find detailed explanations that answer your questions. To make sense of it all, Ilya Grigorik and I focus on useful things developers should know to speed up their web apps. We also talk about HTTP/2 and how it's different from HTTP/1.

Ilya is a web performance engineer at Google, the co-chair of the W3C Web Performance Working Group, and the author of High Performance Browser Networking.

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2:42 - You're a Web Performance Engineer at Google and the co-chair of the W3C Web. Perf. WG. What does that mean?
4:50 - How do you gather performance data?
7:58 - So part of the W3C group's responsibility is to find, create, or refine APIs that help people with performance?
9:45 - Is there one thing people do that really slows down their pages?
11:58 - How does PageSpeed Insights work under the hood?
13:40 - How can you minimize the number of bytes being transferred?
16:50 - Is Time to First Byte still an important metric?
19:30 - What does Waiting (TTFB) in Chrome's DevTools really represent? Is it how long the browser waits for a response from the server?
20:24 - So is the Waiting time just time waiting for my server?
21:05 - Then we must shorten the network trip time and speed up the server response
21:35 - Can we measure the network trip time separate from the server response time?
22:50 - After that, how do we minimize the Content Download time for faster content display?
24:30 - How can you test on slower networks if you have faster internet?
26:28 - Would you recommend a speed-first approach when developing apps?
27:55 - It's hard for developers to think about performance when they're crunched to complete deadlines
30:40 - How can you convince your team to spend time and resources on performance?
31:20 - What kinds of things block the loading of additional assets (or block rendering)
33:20 - What does the Critical Render Path look like?
34:00 - How can we make sure JavaScript doesn't block this render path?
35:40 - It doesn't make sense to have scripts at the bottom of the page
36:10 - What if your scripts have dependencies? Can you use async?
37:30 - What's the difference between async and defer?
38:36 - How can you measure if using async is beneficial to your app or hurting it?
40:25 - DevTools can be overwhelming. How can we get a better understanding of how to use it?
44:00 - Why are there (sometimes) empty blocks on DevTools' waterfall right before a file is loaded?
46:25 - What is different about HTTP2?
51:35 - Do we still need to concatenate and minify with HTTP/2?
54:30 - What's one thing you're working on that's really exciting to you?

How to get in touch?
Ilya's website is where he posts a lot of interesting information. https://www.igvita.com
He's also active on Twitter:   / igrigorik  

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