And I feel for them, but inside my head, based on the interview, I'm thinking "well, it's probably not strictly due to age, but rather that your experience has left you with strong opinions about things and as a natural response makes you less flexible to new ideas."
Based on this insight, I regularly catch myself making my own assumptions and yeah, I'm often correct, but I still want to maintain a healthy dose of self-skepticism.
Sometimes, I'm wrong. And sometimes the paradigm has shifted to a new model I am unfamiliar with.
I have found that as I get older it takes longer to find a job, but I don't think it's ageism. It's just that I have over 30 years of experience, and I want to be paid accordingly. But you see job postings for "senior software engineer", and they want 5 to 7 years of experience. If that's what you need, then I'm not your guy.
There are employers who understand why I'm worth more than the younger people, and who will pay for the experience. But there aren't as many.
I have been overlooked or talked over in some scenarios because I am younger. I have even been told I can take a hit for the sake of office politics because my career has plenty of runway.