Web performance in the real world: how to make fast websites

There is boundless advice out there on how to improve web performance. Some folks will tell you to avoid complex CSS selectors, others will tell you to reduce your JavaScript bundle size, and others will recommend fancy Babel plugins to Webpack your worries away. In practice, it's never as easy as going through a checklist – especially if your checklist of potential optimizations is hundreds of items long! In this talk, I'll explore some of the work the Microsoft Edge team does to help website authors build faster sites, and in particular how to think of performance as an investigative activity, beyond the checklist approach.