As an employer hiring or employing full stack web developers, do you pay attention to the looks as much as the functionality of the websites or web apps in the applicant’s portfolio?
Both. I’d however lean towards functionality more as you can always get a UI/UX dev support person on a short term contract.
I’d say both. Even if it were a white page and it’s functionalities are on point, there is a market for it. Add a banging UI with super UX, and you are on your way to stardom.
What is most important is UserExperience, does it do what your users want, do they find it easy to use, are they happy? design is subjective what is beautiful to a group is not to others. Great sites has first good user experience.