And those fields will have plenty of capable people who don't get a shot with the best firms because they didn't go to the right schools, or know the right peop

And those fields will have plenty of capable people who don't get a shot with the best firms because they didn't go to the right schools, or know the right people, or use the right buzzwords on their resume. The coding screen is a less dirty shirt in a pile of dirty laundry. At least it's an objective measurement, even if it doesn't measure precisely the right thing.