There is no "you can only go up" trajectory to development experience. A 30 year old might be half the developer they were at 23, due to burnout/disillusionmen

There is no "you can only go up" trajectory to development experience. A 30 year old might be half the developer they were at 23, due to burnout/disillusionment/less time. Developers can flounder after previously being excellent. I've seen it. Something I've also seen a lot is developers getting promoted to levels they cannot handle, and imploding as a result (it's hard to recover from this). Some people could not lead a project with 30 years of experience. Some people could lead a project with 0 years of experience. Age is basically irrelevant.