Shameless plug: I’ve been a “technical” UX person for my whole career, and a big fan of (and trained by) the Nielsen Norman Group, mentioned elsewhere in this thread.
I’ve always enjoyed this “principles” approach to UX design and wrote “101 UX Principles” in 2018: https://uxbook.io - please do check it out, it’s ideal for non-UX specialists to understand the usability reasons behind common design decisions (and mistakes to avoid). Plug over!