So the HN candidate had a website that a business was based on? Or the candidate just had a good "fake" website that has a lot of good business code in it?
1) Some amount of professional experience in the technology we were looking for a contractor in.
2) An attitude that boiled down to “I write software to fulfill business objectives.” (The opposite attitude is what I characterize as the “hipster coder,” who says “I couldn’t possibly work on your legacy system unless you agree to rewrite it from scratch in $hot_new_stack.” Yes, I have literally had a contractor tell me that before, about a webapp based on a 5 year old front-end framework.)