Echo JS 0.11.0

Well, if you need your CSS handled like you want for example. How about setting some plugins for PostCSS, configuring Sass (with parcel you do it using package.json),  If you are building a large project you will need configs, sooner or later. How about aliases? I stop now ;-)

then you are configuring PostCSS and Sass, but parcel itself is zero config. I think Fusebox could learn a lot from the #0cjs trend, just like webpack did with v4

Zero config is good for getting started, but a large project needs some solid configuration.