The churn of knowledge can be limited by choosing technologies that don't require constant adaptation. (Time to offend the .NET fanboys): If you pick .NET, there isn't that much difference between .NET Framework 4.5 (from 2012) and the latest version of core. The job still gets done, just with a different set of packages. If you don't have a use for async/await or the TPL, you can go as far back as 3.5 (from 2007).
> I am not from USA and have no degree. I am 41 y/o and I'm a self-taught programmer ever since 12 y/o. Not sure how well that flies on interviews; I feel the US companies put a lot of value on degrees?
Some do, but with 19.5 years of experience, this wouldn't be much of an impediment for you in the United States. All of my opinions apply only to the United States. I haven't worked in other countries and can't comment on them.
> They'll require a ton of time and attention every day.
IMO, a "code janitor" doesn't just sit around all day reading HN. When I use those words, I mean the type of job where you're expected to fix bugs and implement features and not much else. Even if there is talk of higher expectations, there are never any consequences for just going with the flow. You'll rarely/never be asked to work overtime or learn on your own time. You'll only pay lip service to clean code, clean architecture, and long-term thinking. You'll still be expected to show up by 9, hang around until 4, and not screw off the whole time. The job is still a job; it just doesn't strain your brain.
> I'd agree but I've neglected networking -- both physical and virtual -- for most of my career and now at 41 y/o I started to feel the negative effects of that. :|
Headhunters are the antidote to this. When a recruiter wants to connect on LinkedIn and have a short phone conversation about an exciting new position, you always say yes. And if they're not sending connection requests to you, then you send the request to them.