Can you provide some guidance/links to a backend Java developer who wants to learn & use a quality long-term, front-end tech stack? Is there a kickstart example project for your preferred stack? Note that I prefer to avoid nodeJS for any back-end production use but am ok with it as part of the dev toolchain, if required. Thank you.

I would say just start with the React tutorial and use the react-create-app (uses webpack etc in the background and is a npm package) that they use in it. Then after the tutorial I would go into the docs and read through them and maybe test some.

After that I would pick the state management tool I want. Either Redux or Mobx as both are popular and have their advantages and disadvantages. I think it is worth going through both their official tutorials as they are pretty good.

https://facebook.github.io/react/tutorial/tutorial.html

http://redux.js.org

https://mobx.js.org

There are of course tons of videos but I think the official tutorials are a great start and using react-create-app instead of trying to dig into webpack and all that is really good at the beginning.

Stick to https://github.com/facebookincubator/create-react-app/ and you'll be golden. If you need more config later, you can "eject", but this is a one-command-and-go kind of thing that is well maintained and works great.

Try Expo at expo.io. It's similar to create-react-native-app but gives you a nice simple tool to preview your app.