Yeah (18 years of exp here, so not quite 20+), I'm getting lots of messages on LinkedIn. I turn the more promising ones into interview calls.

The interest is mostly based on a combination of fairly strong CV overall and familiarity with a couple of technologies which are currently in vogue in my niche (Scala development). I'd say you need at least one of those, and preferably two. Without it, you don't seem to bring in more (perceived) value than the guys in the 5-10 years of exp bracket, and you'll probably be more expensive and/or possibly harder to manage.