I'm wondering if Bolt is able to combine and minify assets like CSS and JS. I found something in Symfony that is able to do so, http://symfony.com/doc/current/assetic/asset_management.html
I haven't found anything about it, but it would be a really great feature.
Bolt doesn't by default. I know most people do things like that using either Gulp, grunt, or some webpack-ish packager.
the postcss extension can do that, but it's not built into bolt, and mostly works for setups that use css variables.