React rendering strategies: Get the most out of performance, keep bots happy

Rendering your app on the client is expensive. Quite expensive if you’re using a library such as React. Applying a Server-Side Rendering strategy was the best solution to improve metrics like First Contentful Paint, and enhance the support for crawlers. Until now.

How can we improve the user experience in terms of performance while keeping the best support for crawlers? How can we mitigate the hydration cost? How to definitely improve our Time-To-Interactive metric of our React application? In this talk, we will share some of the techniques we have been using in Adevinta as well as our insights after applying them during months in production. We will explore what Dynamic Rendering and Progressive Rendering are, their benefits over the performance, the limitations of each one and how to implement them.