Nice article, but can you reveal your sources behind npm as build tool best practice? I have never heard of this approach. I’m huge supporter of npm scripts as task runner, but I would never use it as a bundler.

I would suggest you to look at great talk by Kate Hudston https://www.youtube.com/watch?v=0RYETb9YVrk where is nicely explained how you can use npm scripts as task runner properly and of course you should use bundler like Webpack.