This isn't about myself, so kindly bare with me. I'll try to make this question as generic as possible.
I already read U.S. humanities professors: Can you get back into academia if you leave? and Does taking an academic job in Asia or Africa make it difficult to get a job in the US or Europe later? but they aren't a good match for my question.
A friend got a PhD in mechanical engineering at 2000 from a tier 1 university in US. Then he moved back to his home country and started teaching there. Now he is back in the US. His computer skills and knowledge of industry related softwares are limited. He just taught core mechanical engineering courses with 2-3 national papers published. His English is very good though. No problem there.
What are his best options of teaching? I initially thought that he would be able to teach in (community) colleges, but then most colleges are teaching CS, social sciences, economy, healthcare, math or at best chemistry. Most of them don't have anything related to engineering, let alone mechanical engineering i.e. thermodynamics, heat transfer, fluid mechanics, etc.
Currently what I'm thinking is that his best option is to just teach math in colleges. Are there any better solutions?