1. You came across as you were the one, respectfully your vetting is not great.

2. Yes, I did not missed that... the tech stack was not on the job posting?

3. I disagree here as I have had worked and currently work with a lot of domain experts, PhD's, and published papers. The gap between what they know, and a systems that works with that knowledge is gigantic. When building software for them you can leverage them, learn a ton, and make sure you narrow down the field of view on the subject so that it is actionable as a software product and you will have great success on it.