And when you do get to the on-site, you may be met with (as I have and few others I've known have and some on HN have mentioned) a junior interviewer who isn't prepared to understand that they don't understand the problem maybe or its optimal solution, and that they are making a coding error, not matter how generously/graciously you put it. And then you have to allow them to come back to you and apologize for their error (which is fine- everyone is always learning, and no one has to be perfect!) after which they proceed to not hire you and hire a younger, less experienced programmer for the job. So yeah, ageism.
