I'm 51 and I've been programming since I was 21. I write code every day. I love what I do and I have never been more productive than I am now nor have I ever written better code than I am writing now. I write highly complex multi-threaded algorithmic code that operates on extremely large graphs (up to 3.5 billion nodes). I have no interest in getting into management.
I did get "lucky" in that I was a member of the founding team of a publicly traded company and am now a technical co-founder and chief software architect of an up-and-coming engineering software startup. I've written 3 blog posts in career and, except for LinkedIn, I participate in no social media/networking. I've never posted on StackOverflow. Outside of my niche industry, I'm sure that no one has ever heard of me. And, that's exactly how I like it.
I'm glad to see coverage of bootstrapped startups and the supportive comments. I've worked at both highly funded startups and most recently I've worked at a profitable bootstrap for the last 3.5 years. The bootstrap startup is definitely more fun... It's nice that we don't have any investors to answer to and micro-manage every aspect of our business and that also have their hands out to get paid first when an acquisition event occurs.
