Ensure zero build errors in developed code?

Answer 1

Hire a professional software developer for the required languagesl(s) and pay them well.  If you want to do it yourself, you literally have to know the language(s) and the compiler(s) well enough to FIX every error reported during a build.  But, even that won't be sufficient for a properly working piece of software.  Hire a pro.

Answer 2

yes, that's your job. what about it?