Probably repeating what's been said elsewhere, but older devs are also less common because a lot move out of development and into management or other areas that

Probably repeating what's been said elsewhere, but older devs are also less common because a lot move out of development and into management or other areas that are either less stress or more lucrative. A lot have kids and their priorities shift, taking large company pay and stability (such as is is) over startup lifestyles. Also, wisdom doesn't always come with age, but eventually you realize that being a developer at a startup is overrated financially - it primarily is a great professional development period. Once you've learned what you can from the experience, you tackle some bigger problems that typically cannot be solved by 3 guys working 24/7 on ramen and shoestring funding.