That the percentage of developers over age 40 is lower than those under 30 could just be the result of demographic shifts: many more people per year were entering the profession in 2015 than in 1995.<p>Which is not to say that ageism doesn’t exist or isn’t a problem. (As a developer and hiring manager nearing 40 I’m making my own career decisions with ageism in mind and also considering the possibilities for “beating the market” by hiring older engineers.) Just saying that you need better data to make that argument.