The term ninja makes me think that the people running the company don't understand software development and have relegated it to a category filled with mysterio

The term ninja makes me think that the people running the company don't understand software development and have relegated it to a category filled with mysterious doings. I expect the same sort of folks to call it wizardry or magic. Hacker isn't as clear-cut a term because there are several different trends in the industry using the term in different ways. Are you a 40 year unix veteran who hacks things together or are you a front-end hipster-stack web developer claiming the title? No, most likely the folks using this term on a job posting are trying to seem youthful, but I can't be certain. I just avoid it as much as possible and, like the others commenting, prefer traditional terms that have legitimate and clear use in the industry. Think about what is implied for a software architect role vs a web developer. There's much more differentiation in the denotation of those terms than ninja/hacker.