Nicholas C. Zakas with a follow up to Philip Walton’s article.
Front-end engineers are, of course, specialists. We care about things that seem insane to others: understanding differences between dozens of browsers, pixels vs. ems, PNG vs. JPEG, compatibility of JavaScript APIs, how to construct a DOM to represent a UI, and so on.
The things I look for in a front-end engineer have little to do with traditional computer science concepts.