If you know how to build complex custom WordPress themes using the starter theme known as _s (Underscores), you can create nearly anything you can dream up. In this course, Morten Rand-Hendriksen shows how to build a theme piece-by-piece by breaking it down into sections including the header, menus, images, index pages, and more. Along the way, he covers key development concepts like using Sass and Sass partials to style the theme, using Gulp to process your code, understanding the WordPress template hierarchy, customizing JavaScript to work for your theme, and more. To wrap up, Morten covers the Customizer and focuses on new features like responsive images.