Ask HN: What's the most basic technical knowledge every NTF must have?

NTF: Non-technical Founder.

Let's assume a person who either has a technical co-founder or has enough cash to outsource his development.

What are the areas that this person has to master to run his business successfully?

- Should he know the basics of every technology? (e.g how does internet work, what does TDD mean etc.) - Should he know how to code? - Should he know about the technology trends?

I am trying to find the fine line where the technical co-founder should aim to reach with minimal effort. Thanks for helping!