There is one more fundamental reason. When you getting aged you have less time to stay tuned with all changes in your field. Of course, if you have a contract t

There is one more fundamental reason. When you getting aged you have less time to stay tuned with all changes in your field. Of course, if you have a contract to maintain some old system, or playng a key role in some long project with solid finance - that is ok. But on the field motivated younger guy will easily outperform you, because you have many things to do as an adult. You simply cannot spend days and nights with laptop. So, there are two obvious directions how to reuse your experience - project management and work as a system architect. But these positions are rarely vacant, so, you probably should start your own project or a joint venture. There is no use to try to compete with younger generations on their field (coding). It is much better to reuse your own experience and use thier energy, naivety and enthusiasm.