After you get old, say past 30 or 40. Can you still keep up with the young coders from your company, those fresh out of school, who can code for 15+ hours on 10 cans of redbulls (most people in Google, Facebook, etc) ? And given the lightning speed with which today's programming frameworks and architectures evolve, can you keep up with the most up to date stuff and be as proficient at them as the next college grad?

I know for jobs like unix/c/embedded programming, it might be that the older the better. But for programming jobs in say web development, social media, search engine technology, etc. Do you become less and less competitive career-wise versus youngsters? For example, most coders in Google and Facebook, I believe are under 25 years old.

In other words, once you reach a certain age, would it be unwise to continue to be a coder, and is it better to try becoming a project manager or architect?