When do you want to know you are dealing with real applicant?

Been hearing from colleagues about a flood of applicants, and within those, a large majority have no business applying (i.e. no visa support, not in appropriate city, not right general skills, fake person).

So how early in the process:

1) initial resume upload & pre-screening questions 2) second pass for more info 3) initial discovery call (5-30 minutes)

TIA.