I freelanced for Everlane over a course of a year where I built out splash/marketing pages for new products and special events. The backend interference is somewhat of a glorified text editor, similar to what codepen uses, however, the code is limited to html, SCSS, and CoffeeScript. Although, the site itself is not responsive, it does have a separate mobile build structure when a mobile device is detected in the browser (e.g. ?mobile=true).
Everlane is a startup clothing manufacturer based in San Francisco. The site is built in react with a custom CMS backend to create fully customizable landing pages.