Comment by ammon

Author here. Ageism is real, and we'll be analyzing it in a future post. But in this case I don't think it's ageism. I think it's big-company-ism. Startups define themselves in opposition to big companies, and take signs of big company culture as strong negatives (which may or may not be justified statistically, I honestly don't know). But there are great programmers at big companies in any case, and startups should figure out how to hire them.