A mistake is a learning opportunity. Here are some of the mistakes I made in my career.
As a Director
Shortly after inheriting a completely new engineering department (Engineering Operations), I wrote a LinkedIn post asking for guidance on how to pivot operational teams to think as product driven teams. One of my newly acquired teams took my post as a critique of them, believing I thought they were broken.
I was incredibly fortunate that the lead reached out to me to let me know how the team was feeling. I failed to realize one of my new operations teams was not aware they were a part of that overall operational tribe. I immediately addressed the whole team the motivation behind the post and why the pivot could be beneficial with them as well. At the end, they pointed out my miscommunication created a stronger bond of solidarity across the team.
As a software engineer
In an engineering department full of desktop application developers moving to web development, I designed a web framework that abstracted the differences. Code could be written identically as before, with all the same functionality, without the slow and disruptive "post back."
From a technical point of view and short-term team productivity. I was (rightfully) proud of myself. In hindsight, this was a terrible solution. When I left, so did the knowledge of the custom framework and how it worked. Similarly, developers weren't meaningfully better versed in web development. Short term gains at the larger long-term expense. I am so sorry!