With the ongoing discussions around build times, and the recent ones on Parcel and re-engineering Meteor, I’m surprised Snowpack hasn’t been mentioned on the forum yet.
I think it’s relatively new, if I understood it correctly, it is aims to improve the dev experience only (it skips some production steps such as minification ). I watched a recent youtube video about it in React Europe. It looks pretty awesome and I have planning to give it a try.