It's always a red-flag for me when in an engineering organization of statistically significant size (which does exclude YC start-ups, so don't view this as a ju

It's always a red-flag for me when in an engineering organization of statistically significant size (which does exclude YC start-ups, so don't view this as a judgment) there are no older engineers. It isn't just the age discrimination angle. It says something about technological identity and mission: they aren't solving a problem that has a barrier to entry (or they aren't going to be able to get past that barrier). As someone pointed out in the "when an engineer goes to Google, a start-up dies" thread, there's an great value to having people with vast technical knowledge and experience: they'll be able to bring new concepts vs. merely new technologies to the table. Being a founder is a different matter (the risk factor is much more significant once there's a family), but I don't see a reason to not hire older engineers (all else being equal). Disclaimer: I'm <30 myself, but benefited tremendously (earlier in my career) from contact with older engineers.