How managers should respond to defensiveness after feedback March 23rd, 2021

I had a call a few weeks ago with a friend and fellow engineering manager, and we spent most of it talking about someone on her team who wasn’t responding well to feedback. He was performing several parts of his job pretty poorly, but when each time she told him that his work wasn’t acceptable, he pushed back. He argued, sometimes loudly, and refused to make the changes that she was asking for. My friend came to me pretty frustrated, not entirely sure how to respond to this guy. Most managers know this feeling: they’re doing their job as a manager, giving clear, specific, professional feedback but it’s going poorly. What should you do in a situation like this?