A few years ago I was in charge of a small team. One of the engineers was a low performer - according to my manager. After a few weeks of operating in that team I had to agree with him. I could see problems from both code output but also from the kind of engagement he had within the team. The person’s head was elsewhere. At that point I started having some difficult conversations with my manager. He was convinced that putting the engineer on a PIP was the right thing to do. I wasn’t convinced by that yet.
What I noticed after a few more weeks, was the tension between that engineer and the lead engineer. They had some conflicts in the past, and it felt that the lead had pulled rank a few times on him. As a last resort to salvage the situation, I moved the low performing engineer to a brand new team. Alongside him, was someone he had a great relationship with. It was almost a night and day difference. This engineer went from almost no contributions to the top 3 most prolific engineers. But beyond code contributions, was his drive and motivation on getting stuff done.
What this situation taught me is that the environment matters a lot. A single week was enough for a low performing engineer to become one of the most reliable. It also taught me that some people need space to step-up. The issue was not just a poor relationship with a coworker, it was also the lack of room for him to shine. As soon as this happened he was an different person. He was more confident and he felt that he owned this feature. I was lucky that the right conditions were present for me to move him to another team. I do wonder how many people are dismissed under the same circumstances.