I see a lot of "coding-centric" answers, but I think the most valuable asset older programmers have is their experience. So I would say, you go into "project lead" mode (which you could read as management, but I think of that hat as non-programming)
In other words, you sit in the planning meetings & your experience on past projects helps get over that "where do we start" mode. You make sure the proper QA and testing is being done, things like that.
Your day is filled with many other tasks than just writing code. You go home at 5pm & work on your private projects for fun & interest (not that 9-5 is uninteresting, but you don't have the time to "play" so much any more)
In other words, you sit in the planning meetings & your experience on past projects helps get over that "where do we start" mode. You make sure the proper QA and testing is being done, things like that.
Your day is filled with many other tasks than just writing code. You go home at 5pm & work on your private projects for fun & interest (not that 9-5 is uninteresting, but you don't have the time to "play" so much any more)