For me, my passion for side projects rises and falls. Some weeks I'll spend several hours at night reviewing and coding. And others I'll have no desire to look at my computer, let alone review someone else's code. It definitely helps to be given time at work to contribute to open source work.

It's an interesting idea on meta programing! It kinda feels like the magic of using underscore templates, than realizing you can precompile them before serving.

Definitely recommend checking out babel-plugin-transform-runtime. Specifically, only enable helpers and disable polyfill and regenerator.

Optional chaining and slightly do expressions.

Curiosity and practice, like @loganfsmyth said.

i think the last one I coded up was to let me checkout Github PRs locally: https://gist.github.com/jridgewell/a93ca90c53183a6a3ba9392635c77620

Vim/MacVim. I learned to code in notepad, then switched to TextMate and stuck there for years. In college, I was too scarred by Eclipse and Java to ever try an IDE again.

I think I'm the closest to being officially sponsored. I'm a Google engineer that spends my 20% time working on babel, and my direct team donates $100 on top of that. @hzoo is a Behance engineer, and I think he spends roughly 50% of his time on babel? Other than that, we're all unpaid volunteers. There's some backers on opencollective.com/babel, but not nearly enough to sponsor a full time engineer.

We follow the TC39 proposal process, mainly. Anything that's been accepted as a stage-0 proposal by TC39 (and was presented to the committee or has a clear understanding of the semantics). We've tried to outline this at babel/proposals

There's nothing wrong with using new standardized (as in, accepted and official JS syntax and runtime code). The ones you list are prefect examples of official code. Promises are everywhere, and essential to understanding async in JS. Awaits are well on there way to becoming best practice (and mandatory) learning, too. But be careful with "experimental" codes that are not fully standardized (still in the proposal process, per the TC39).