Now that is something I am trying to figure out too, besides how to make a machine sentient (although, I see greater chances of me succeeding in with the second one). A software developer at mind, but a physicist at heart, I am always going down rabbit holes and simply ask "How does that work?". This mindset has landed me at the foundations of machine learning and computer science, but also hardware development and physics.
I get excited most if a project combines machine learning, hardware constraints and a research question. In that case, don't expect to see me anytime soon.