But having had several years of experience building web applications in Rails, handing data carefully between templates and controller code and managing the leaky abstractions for those places I actually had to use Javascript, I do not miss that experience at all. I'm not a front-end developer (I do it when I have to) and I am 3-5X more productive in React than I ever was at Rails front-end. If that's the return a nonspecialist gets from the React stack, I can only assume someone who specializes in it does even better.