The hardest part of the first year was not the decisions. It was noticing how many decisions I was making by accident — in a code review comment, in a hallway answer, in the pull request I quietly rewrote instead of explaining.
Writing code is a closed loop: you get an answer in seconds. Leading is an open one. You say something on a Tuesday and find out on a Thursday three weeks later whether it helped. Learning to work without that fast feedback was the real adjustment.
Three things made the difference: writing decisions down so they could be argued with, giving problems away instead of solutions, and protecting a small amount of my own hands-on time so I still understood the system I was making calls about.
This is an honest account of what worked, what I got wrong, and what I would tell someone stepping into the role next month.