Full disclosure—I am a professional in communications and strategy design, not UX. Therefore, there are fewer opportunities to interact with engineers. Nonetheless, this is an interesting subject, so I have a few comments to share about where I expect design differs from engineering...

Design is innately bottom-up—starting and ending with understanding the human and cultural context of both the problem and solution.

The design process also tends to be more abductive than inductive/deductive. This can enhance the potential for innovation. As such, I sometimes think of designers as solution-finders more than problem-solvers.