Vercel employs maybe half [correction, maybe a quarter] of the React core team. For example, at the keynote at React Conf 2025, it was mentioned that Andrew Clark, who, if I am not mistaken, is employed by Vercel, worked on resolving the rendering issue of React that was blocking the release of React 19 after it was discovered in the release candidate.
Vercel and Next.js have been the main testing ground during the development of React server components as well.
How much has Vercel contributed to the development of react over the past years?
Vercel is the primary driver of react SSR / server components, which has also led to an explosion of complexity in react and has made it less useful as a composable library imo.
The last truly useful react feature for me was error boundaries in React 16 (2017?) and I think hooks was react 16 too?
These days if I need ui components for an existing SSR app I just use web components or lightweight libs like mithril.
Vercel and Next.js have been the main testing ground during the development of React server components as well.
How much has Vercel contributed to the development of react over the past years?