One of the exciting things about web development is that the underlying technology that we use is constantly evolving. It’s hard to believe, but Server Components, partial hydration and hybrid rendering are no longer experimental features and are here to stay. With more projects adopting these newer patterns for client side rendering, the challenge now is to ensure that these applications can scale and that there are not new performance and reliability challenges that have not yet been fully considered. We’ve begun to encounter a wide range of new issues that include hydration behavior that doesn’t work the same way every time, rendering waterfalls, delayed streams and more, as well as some of the more subjective performance regressions.
So you’ve built this amazing React app, and now it’s time to deploy it to production. But what actually happens when you type in your username and password and hit submit? Let’s take a closer look and skip all the boring parts about React and focus on the low level details of what’s actually happening and how the browser turns your state into pixels on the screen. We’ll get into why hydration mismatches happen and how to figure out why they’re happening to you. And finally, we’ll look at some actual tools and techniques that you can use in your app to improve the user experience, squash weird rendering bugs and make hybrid rendering easier to understand and manage.
This talk has been presented at React Summit 2026, check out the latest edition of this React Conference.
