At PreviousNext this past year, we have started using a style-guide-centric approach that matches our Agile development practices. We write our styles and markup as components and then use automation to build, test, and add them to a style guide.
Since we are a Drupal shop, you might expect that all our automation is done with PHP, but weβve found, on the front-end side, the best tools are written in Node.js. Grunt, Gulp, Yeoman, Bower, Eslint and more are all written in Node.js and installed and distributed with its package manager, npm.