I can attest that many tech companies are hostile to older people. I'm a white male in my 40s, and I've felt it myself and heard many more accounts. The existence of counterexamples doesn't falsify the claim.

The temptation to blame victims is strong. I think it comes from wanting to reassure oneself that "it can't happen to me." So you have to actively silence that voice in your head, and assume that victims are actually victims unless there's real evidence to the contrary.

As advice for senior people, I'd suggest: don't apply for junior jobs. Apply to lead large teams, or start your own company. It can be more stressful than coding, but that's the way the industry is structured.

The software industry has few required degrees, certifications or titles. There is no rigid career path or unions forcing companies to retain people they have had influence over for a long time. This is great for people starting out, but like everything else there is no free lunch. It is entirely possible, even likely, to navigate this wrongly.

General experience doesn't mean much since there are few standards. Ones experience would generally be used to take more responsibility, do more important things or in other ways advance ones career. Not as some measurement of quality, since that would be very subjective.

In a changing industry it would even be expected that when things change a certain amount of people won't last, because they get squeezed out between new people coming up and old people already specialized.

So while surely part of the industry focuses to much on youth I think people jump the conclusion that it is widespread too quickly.

I apologize if I made it seem like I was blaming the victim; I was genuinely interested in learning how one would know the reason they were rejected. I've often been rejected and wondered why.

I don't at all find it hard to believe some interviewers would be biased against older candidates, especially for junior roles. However, given the person who posted seemed to have such a wealth of knowledge and experience, I was very surprised that they wouldn't have a very easy time finding a job even if places that refuse to hire older workers exist.

Well, I'm sure nobody's ever walked up to oceanghost and said, "I'm not hiring you because you're an old(er) white male" (although, unlike every other possible form of discrimination, that would be perfectly legal), he just probably has a sense that this is what's going on based on the attitudes around him. But I doubt that the author of the linked article has ever had anybody come up to her and say "I'm not hiring you/promoting you/supporting you because you're a woman (or 'of color')", either - if they had, I suspect it would have worked it's way into her article somewhere. Instead, she just gauges the attitudes of the people around her and makes her best guess as to why things aren't working out the way she wants them to. If her suppositions are reasonable, then oceanghost's are, too.