One guy I worked with whom I would describe as a 10x programmer was not only unbelievably productive as a software engineer, but he had a fantastic attitude. He was the antithesis of arrogance and was universally beloved. He was both a leader and a genius, but the first word anyone would use to describe him was "humble" (and not in a self-conscious or ostentatious way). He was enthusiastic, open to new ideas, intensely curious, and was also notable for how much he wanted to see other people succeed. I've never met anyone else like him.
