How to optimize the hydration process in SSR applications to speed up time-to-interactivity?

Hydration in server-side rendering (SSR) is the process where client-side JavaScript traverses the static HTML code pre-generated by the server, finds the corresponding DOM elements, and attaches event listeners to them, turning a static page into a fully functional interactive application. The main problem with classical hydration is that the application remains completely blocked and unresponsive until the entire volume of code is loaded, executed, and bound to the interface, which creates a significant delay on slower devices.

To solve this problem, modern web frameworks are introducing advanced approaches such as partial hydration, lazy hydration, and resumable hydration. These technologies allow loading and activating interactivity only for components that are in the viewport or require the user's immediate attention, leaving the rest of the page static until a real necessity arises.

You can improve hydration performance in your project with the following steps:

Proper management of hydration allows you to significantly reduce the time to full page interactivity, improve performance metrics on mobile devices, and lower the CPU load on the client device.