I once took part in a project where we created a QML based implementation of a previously Node.js based embedded app. Node.js took ten people two years, QML thr

I once took part in a project where we created a QML based implementation of a previously Node.js based embedded app. Node.js took ten people two years, QML three people six months - and no callback hell. Lots of caveats though: I'm not sure how experienced the Node.js guys were - team QML was fairly experienced (and competent in general). JS GUI frameworks have improved a lot respectively become available in the first place. Recreating something is always easier than creating it the first time. We used the same backend parts that were probably co-developed with the Node.js frontend (but AFAIK not counted in the two years, ten people). We heard that the Node.js version had quite high velocity initially, but slowed down greatly when it came to polishing. Like more than half of the time spent on the last 5%. The QML version also ran more smoothly.