I'm also directly involved in hiring for my team, having helped add 15 members over the last year, working directly w/ the director to review all resumes, handling maybe 30% of the screens, and usually the veto vote. We've interviewed a number of engineers in their 40s and 50s.
Experience is great and we're always welcoming of older devs... but there is a caveat. If that experience is tempered by a somewhat pessimistic attitude, which is often the case, there is rarely a chance to move forward. It's not being old - it's being worn out.
AFA the resumes of older devs, we often cut them out because they're an objectively terrible, wall of text mess that goes on for 4+ pages. Like 2/3 of the time this is the case.