Our developers use react right now and I'd be interested in learning more about it! I assume it's React.JS because it's for a web application and not mobile. I'd be interested in both options, but react.js may be more directly applicable to me right now as a designer.
At this point, I'm actually talking about React Native, which is for building mobile apps, instead of React.js for the web.
But perhaps something about React.js / Vue.js can be good too if there's enough interest. :)