React's rendering is synchronous by design. As a result, rendering on the server is left as an exercise for the rest of the community to figure out.
There are some cludgy solutions for this, most of which require having
fat handlers components controllers at the top of your application
that are responsible for marshalling data for all components under them.
For a non-trivial application, this means mixing concerns between your specialized components and the controllers, which is conceptually difficult and programmatically annoying to maintain.