Hi Marc! I loved your list!
Under the well-rounded I would also encourage developers to learn the basics of marketing in addition to design. At least the technical aspects of it. This means making sure there are hooks in your markup for marketers to use with GTM, knowing how the GTM Data Layer works, knowing enough to NOT block the bubble-up when a form is submitted so marketers can track form submissions, and vanilla JS/basic GTM tags/triggers/variables because not every shop has a Technical SEO person who knows JS.
Hi Marc! I loved your list!
Under the well-rounded I would also encourage developers to learn the basics of marketing in addition to design. At least the technical aspects of it. This means making sure there are hooks in your markup for marketers to use with GTM, knowing how the GTM Data Layer works, knowing enough to NOT block the bubble-up when a form is submitted so marketers can track form submissions, and vanilla JS/basic GTM tags/triggers/variables because not every shop has a Technical SEO person who knows JS.
For design skills I always recommend:
Don't Make Me Think - Steve Krug (This was the only textbook I had for my uni design students.)
Better Web Typography - Matej Latin
Refactoring UI Channel
And there is now a Refactoring UI book!