I recently went through the instant interview/rejection process at an up-and-comming SV start-up, and can relate to the OP's confusion. I am also in my 40s and

I recently went through the instant interview/rejection process at an up-and-comming SV start-up, and can relate to the OP's confusion. I am also in my 40s and at first wondered how the obviously flawed process could produce reasonable results. The number of false negatives must be staggering. I think the key for them is that incoming volume more than compensates for missed opportunities. This is the luxury of the hyper-successful. I think that for a business owner (or very busy engineer in my case) applying into these types of organizations, you need to expend a lot more effort on applying, researching and preparing for the actual interview than on the specifics of your skills and/or business.