I'm 60.
I've probably done my most meaningful work, in the last 15 years. I feel that I learn more quickly -and better- than I ever did, when I was younger.
It's hard to get 10K hours into anything, these days, as tech is a moving target, but it's doable.
Being OCD (like me) is helpful.
These days, I specialize in Swift programming, for Apple devices. I'm really obsessive about it (My GH Activity Graph is solid green, and it's pretty much all Swift[0]). Even with writing Swift, every day (since the day it was announced), I feel as if I'm just barely keeping up.