It is not. I think the idea comes from the fact that people have this idea of "developers" as people who work for startups or FAANG companies. Most developers work in unsexy industries and in boring places. Insurance companies in Indiana, a hospital Utah, an manufacturing plant outside of Houston, etc.

There's also the fact that middle-aged developers raising families don't have time to blog and be "influencers" on social media.

That being said, ageism is definitely an issue in the industry. A lot of it has to do with so many companies having an "FTE" based approach to viewing things. Some moron with an MBA and no actual real-world skills sees a 55 year-old developer and thinks, "I can replace him with two new grads and still have money left over".

FWIW here's some data from the 2020 Stack Overflow developer survey: https://insights.stackoverflow.com/survey/2020#developer-pro...

To what extent is the survey representative? Hard to say. I'd be interested to see other sources of data.

This probably is true. The industry has been growing quickly for decades so there will naturally be far more people with ten years' experience than thirty years', say. Most people who enter the industry are young, so you would expect the demographic to skew young.

I also wonder what the median age is for different technologies. I'd assume that developers are younger in frontend/mobile apps than in backend or C++ enterprise software.

I think it’s a perception. I’m a youngster in my business unit (500 engineers) at a spry 39.