To read more, see my complete deep-dive on O.o() over on HTML5Rocks.
If you have complete control over your server, an excellent PageSpeed Module for Apache and Nginx exists with filters for many of these tasks. If not however, or you feel the module isn’t quite for you, a number of build-tasks exist for tools you’re probably already using to fill in the gaps with more granular control.
For a complete list of Gulp and Grunt tasks the Yeoman team recommend for your build process, see my complete write-up on the Yeoman blog.
I'm an engineer at Google working with the Chrome team to build tools to help improve developer productivity and satisfaction.