Grunt + Browserify + Babelify

Run:

> npm install
> time grunt

Results:

Running "browserify:dist" (browserify) task
>> Bundle js/index.js created.

Done, without errors.

real    0m6.742s
user    0m6.262s
sys     0m0.546s

Ouch! Likewise...

> time browserify index.js -o js/index.js -t [ babelify --presets [ es2015 ] ]

real    0m5.398s
user    0m5.025s
sys     0m0.431s

What about Babel-CLI?

> time node node_modules/babel-cli/bin/babel.js -o js/index.js --presets es2015 < index.js

real    0m5.462s
user    0m5.067s
sys     0m0.456s

The solution

Use NPM3! Flatter dependency trees = faster builds.