Nor should we live in fear. I'm 41, and still doing quite well (as measured in both happiness and dollars) coding every day in a comparatively senior position. I don't expect that to change any time soon, though obviously I recognize that it can.
Do what you love. If you're good at it and willing to compromise reasonably, then the market will accept you. If you're not good at it you will have trouble sustaining a career for the simple reason that "junior" hires are made with the hope that the employee will improve; that prospect seems much dimmer for middle-aged candidates.
And the willingness to compromise is important too. If you are focused on a very narrow field, you may find it dissolve due to technological progress and market conditions. If you are focused on progression inside a single large employer, you may find its culture doesn't want senior hackers. Be broad, be flexible.
Do what you love. If you're good at it and willing to compromise reasonably, then the market will accept you. If you're not good at it you will have trouble sustaining a career for the simple reason that "junior" hires are made with the hope that the employee will improve; that prospect seems much dimmer for middle-aged candidates.
And the willingness to compromise is important too. If you are focused on a very narrow field, you may find it dissolve due to technological progress and market conditions. If you are focused on progression inside a single large employer, you may find its culture doesn't want senior hackers. Be broad, be flexible.