[srevenant]

General "wisdom" is to only show the last 10 years of experience on your resume. This is for a variety of reasons, but it largely is because there is an age bias. It makes it harder when you have things older than 10 years you want to show, but the X-Y year doesn't matter more than "spent 3 years working on OSS project doing ..."

There are certainly things that try to weed out inexperienced as well, but there are also people who simply would rather hire a younger person because they have a perception that somebody older would be harder to train (right or wrong).

[lordCarbonFiber]

That may be market dependent because I've not seen it with the candidates I've interviewed.

I think the preception of ageism comes from the fact that more experienced employees come with with more expectations (of performance and pay). If you've been in industry ten or twenty years and havent' (by choice or by ability) then you've all but proven you're "harder" (Id say neigh impossible) to train. One of the few metrics that correlate well to performance in knowledge work appears to be ambition so it naturally results in older workers either doing very well or washing out.

The problem, as I see it, is those washouts are the ones crying "ageism" the loudest and doing their best to stifle talent entering the workforce.

[srevenant]

playing devil's advocate: it is easy to claim discrimination doesn't happen when you aren't affected by it--the claim that it is the cause of the individual, no the system, is the usual go-to argument. Try revisiting similar arguments above, but changing them to be about women or black people, and see how they play out.

And for a little flavor, mix in neurodiversity differences. In tech you have people who literally think and act differently. They could be brilliant, but if you expect them to behave and schmooze like your sales team, they are going to wash out. https://hbr.org/2017/05/neurodiversity-as-a-competitive-adva...

Then add to the mix privilege. People who start a few steps ahead, maybe they had better schooling and networks. Somebody who spent 20 years learning the job but starting further behind might be just as good, but just not beginning at the same starting point.

Or, it could just be the fault of the person being old and they should have already succeeded by this point in their life? Don't ask questions, just notice the age and move onto the younger candidate.

Bias and prejudice exists in everybody, we cannot avoid it.