Years ago, I was a senior developer
Years ago, I was a senior developer. I was promoted to manager of development.
Result? I was a lousy manager.
In retrospect, I can see clearly why I failed.
This quote explains why.

My mistake?
I was in the weeds on tech issues instead of removing blockers, trusting, and delegating. I was was “too busy” with details to fix the big picture.
The low-level focus that made me great as a dev, made me a liability as a manager.
My abstraction level was too low.
I quit that management role in about 9 months and accepted a principal engineer role. I was back in the tech, and it felt great. I was back to being highly effective.
But looking back, I now see I could have been a great manager too. I just needed to change my mindset.