I'm 46 and on my 4th founding engineering team. Coding every day, learning new frameworks with each new role. Home for dinner every night with my kids. My coworkers and I are all in the same age range, we've circulated from one startup to the next, some quite lucrative, others flame out, but no one ever questions our abilities. Don't work for the man, especially when the man is just a boy.
Hah, I love it.
Then again, working for older people that think they know something just because old is equally tiresome.