I've been hiring engineers for a few years now and from _my_ perspective, age has never been a consideration. That does not mean other interviewers did not include age bias which influenced the overall decision.
I'm around 30 currently, and I'm terrified as I get older that this will happen to me and my friends. Saving for retirement is, intentionally, a very long process -- and very arduous if you're trying to save to retire in the Bay area.
What are people that push such discrimination thinking about their own futures?