“One of the hardest things I’ve had to learn is that humans aren’t pure functions: an input that works one day and gets one result, then again another day and get an entirely different result.”
Engineers get promoted into management because they were good at code. Then they manage people like code and wonder why the output varies. The person who gives blunt feedback often can’t take it. Asking people how they want to hear things is cheap. Most managers never bother.