Ask HN: What is the avg. age of a silicon valley engineer.

Would love to get the community's thoughts on aging in the valley as a hands on software engineer. My impression of people in the valley - think startups - is bunch of 20 year olds with no direct responsibilities of supporting anybody other then themselves. Coding all day long in the shell is what most of them love. However, inevitably as everybody ages, how does that progression look like in the valley. Do they continue being engineers developing software when they are 35-45-55 or do their roles change.

I would like to see if there is any data indicating the age and roles of people in silicon valley. Would be a very interesting graph/chart. if somebody has the data and are willing to share, I can happily put a visualization together.