Oh my, it is beautiful on the inside. Check out the source. They're totally showing off the power of React component model even when it doesn't render directly to DOM tree: https://github.com/Flipboard/react-canvas/blob/master/lib/Su... It's about describing nested side effects in time, really.
I have generally done systems and backend work, so usually C/C++/Go/Python. React is making me extremely excited to do some frontend work! Is React a good introduction to the land of frontend programming? Or do I first need to familiarize myself with vanilla JS and go bottom up to React?
I think you can build a lot on top of React with minimal knowledge of js (so, yes, start), but you definitely want to go deep and understand how it works inside (so, yes, also study js).