But I did want to explain the typical issue I have seen when interviewing older software engineers that had a long career but shot themselves in the foot by being too tied to a specific technology. At no point did I want to say that it was the case of every engineer I interviewed. And I fully agree that it's often tough dealing with the ageism in this industry.
It takes some politics, and interpersonal trust to get your advice taken seriously. Sadly, this also means looking past the technical details and considering organizationally why certain decisions need to be made. The company might prefer the occasional breach and "we are sorry" PR over spending a lot of money on network security, for example.
Sure, but what about when the choice presented is more along the lines of "Hey, let's spend a little money on network security now so that we don't have to spend millions later cleaning up a huge mess", and is met with the mentality of "You're worrying about nothing." Ummm, no? I'm sharing the expertise for which I was hired?
Sad thing about this is that some of us (like me for one example) have known this since the days before personal computers were even a thing, but it don't really help to stay on top of modern tech when all the people in charge of hiring in the tech industry are twenty-somethings who automatically instantly hate anyone with even a single gray hair or wrinkle visible, and instantly dismiss a lifetime of knowledge based entirely on ageism.
Even sadder is that the "decision makers" in many tech jobs still to this day actively ignore good advice that people like me have been giving since the early days re; things like network security being more important than they want to admit to themselves (just to name a simple and obvious example), and then when their ignorance of such issues come back to bite them in the ass they always scapegoat the "new guy" somehow and out he goes.