My sample set is definitely biased. I see plenty of very conservative (doesn't want to learn, will only work in one technology) junior engineers, folks who are going to stall out. For senior folks I don't see many. This could be because older folks have jobs or are self filtering to the tech they like or maybe their resumes don't make it to my desktop. Of the folks I can recall that were going for a jr position with many years of experience had some pretty obvious personality issues. Everyone else I interview that's been in industry over 12 years is trying for Lead/Staff/PE. I'd definitely want to know why someone with 20+ years of experience in development is applying for a SDE2 job.

"Just needs a job" and "moved into software" are good reasons. But I'd be really worried about "just needs a job" person getting mad/frustrated if they were that experienced and banging heads with manages that didn't know how to leverage their skills.

When I was younger (~2005) I worked as a peer with one of the dads of a kid who was one year older than me in highschool. He actually became a good friend and mentor. I also worked with a guy who had been a CTO of a 500 person dev shop for years and went back to being a dev. He relished not making decisions or dealing with politics. They were both great mentors. It was a 2 way mentorship as I had a bit more core CS than they did and was more willing to experiment on new tech. They were great with doing whatever they needed to to get the job done. And they'd been in many techs stacks, that helped me break my single language bias and my "not my job" quickly.

I think these days my bias would come from everyone I work with that's older is also quite senior, level wise. On the engineering side they're people who are also constantly trying new things and really leveraging their experience. They're all very introspective. You can call into question pretty much anything with them and you'll get a good discussion.

Companies I've worked with definitely expect engineers to at least reach the lead position for the most part. Up or out in some ways. But the megaco I worked at definitely has really solid non-lead, non-entry-level engineers who have been there forever, esp in critical systems, ignoring their up-or-out guidelines. The main risk there was a new manager being biased and just assuming a 15 year tenure L5 engineer should be managed out. As a contradicting factor there was general consensus anyone over 10 years "really knows some shit" as the default assumption.