Clearly that's what they meant when they said fusion: https://fusionjs.com/. - Source: Hacker News / 15 days ago

b) Don't do intermediate builds at all. This is what we do for monorepo-internal packages at Uber. Basically, our framework lets you specify what parts of node_modules should be transpiled when compiling the service. So basically you just have a single compilation step and the performance cost is alleviated by leveraging babel cache. The upside of this approach is you only need one file watching daemon and you... Source: over 3 years ago

I also worked on another framework which does ship with polyfills, but this one is very much a "we-call-you" framework, in the sense that it has an full-fledged, opinionated compiler with hundreds of hours worth of time spent on optimizations, and the inclusion of polyfills is also very much a deliberate choice made in the name of productivity. Source: over 3 years ago

We've gone down this rabbit hole with Fusion.js. The TL;DR: is core.js aims to be standard-compliant, which means it'll often pull in a lot of code to deal with obscure corner cases like dealing w/ Symbols. Source: about 4 years ago

In case UserAgent shows an old browser, show message and offer to go to site: https://browsehappy.com/ and download a modern browser. Source: almost 2 years ago

We actually did do something like this years ago when IE conditional comments were still a thing. We showed a small banner - similar to the cookie consent banners that now plague the web - that contained a message and a link to Browse Happy. Source: about 4 years ago