Huh? Im over 40 its only getting easier to get hired... Not sure where the ageism meme came from other than perhaps older generations who learned compsci pre the internet got left behind a little bit in the made takeoff of software. I am over 40 without a family or partner though, so I suspect the bias is far more about how much of your life is work energy.
What type of companies though? Because startups definitely seem to discriminate. I think partly because it's easier to convince a 20-something that working 6 days a week for mythical equity is a good deal.