My definition of science is something like "a methodical approach to reach some truth" whereas engineering is something like "a methodical approach to reach som

My definition of science is something like "a methodical approach to reach some truth" whereas engineering is something like "a methodical approach to reach some functionality". And I think some version of that is pretty universally accepted. So by that definition, prompt engineering is much closer to engineering than science. That said, I would consider it closer to product development than either of the above two; I don't count 'tell an llm you'll torture it until your website is hopefully less buggy' a methodical approach.