is hilla+react production ready ?

would you encourage someone starting a new project with react today or we should wait a little bit.

ps: i prefer react to lit because of the popularity and reuse of existing css module like material design.

reuse of existing css module like material design.
Just noting, that material design css does not apply to our components as is. So if you use React wrappers to Vaadin components, they follow different theme by default. There is Material theme variant available for our stock components. But that is not real material css, but a look-a-like. So when you design your application, you need to take this into account.

See more: https://vaadin.com/docs/latest/styling/advanced/material-theme

would you encourage someone starting a new project with react today
Yes, but with notion that it is a new product. We do not label it as beta anymore, so it is production ready in that sense. But combination of Hilla + React is very new, and developing apps with it will be a learning experience. We are interested to see how those for whom React is more familiar will adopt it. Note, React as a word has two meanings, the React core library and React as a ecosystem (or canonical stack). Our integration is about React core library. We do not claim that everything in React ecosystem is working with this combination. On the contrary, there are some specific thing that Hilla replaces, like the backend communication. Hilla + React is best suited for those application projects, where you do not have existing REST backend. I.e. where Spring Boot Java + TypeScript frontend architecture is a natural choice. Also there are numerous 3rd party utilities in React ecosystem that may not fit nicely to our stack, and some other may actually fit well (like Formik). We are just in the start of the learning curve regarding these.

Thanks for your thoughts on that.