Most of the age discrimination I've ever seen has been anti-Boomerism, not specific fixed ages. i.e. it was "people over 30-40" 20 years ago, and now is basically mainly against people in their 60s+. I've never (as far as I can tell) experienced age discrimination, and I'm >40 now. There may be passive age discrimination (incompatible schedules for people with families, etc.), but most of the companies I've interacted with have been explicitly pro-family which goes against thag.