An employee intimidating others team members

Problem

I was working with a developer who was individually excellent, but very bad when it came to working in a team. He could handle complex tasks better than others, but when he was working with other people he was condescending. During meetings, he spoke louder and intimidated others to impose his decision on people. During code reviews, instead of trying to understand other's propositions by asking questions, he would be very prescriptive and say "What you've done wrong is...". He also regularly complained about other engineers' coding styles in front of them. I progressively noticed that, intentionally or not, he was being a bully to the rest of the team. Other people didn't dare to ask him for help and didn't share their opinions freely when he was nearby. They also discreetly avoided being assigned to the same projects as him.

Actions taken

Once I became aware of his negative impact on the team, I took action. I talked directly with him and made him aware of the situation. I let him know that his attitude was deteriorating the team's atmosphere and productivity and that if it didn't change I would have to take action. After this conversation, I coached him before every pull review and meeting and set up clear expectations about how he should behave, saying he should listen more to his co-workers, consider their ideas, be more constructive in his comments, and offer his help. I saw some improvement, and his peers gave me some positive feedback, so I became less involved and dedicated more time to other subjects. However, every time I became less involved, he would fall back into his bad habits, so I would react by spending more time with him, and coaching him. This scenario lasted for months, and at the end, I decided that it wasn't a good use of my time, so I finally let him go. It was a breath of fresh air for the whole team. Meetings went better, people started telling jokes, and the overall productivity and collaboration of the team drastically improved.

Lessons learned

The main lesson I learned is that I should have acted earlier. I spent so much time on that one person that the rest of the team was not getting the attention they needed. However, the real question is: How could I have acted earlier? The first thing to note is that it took me some time to realize that there was a problem because I was a young manager and at first I was impressed with his technical skills. What's more, he worked several times on projects on his own so I didn't notice he was bad at working in a team. I think that I should have also set myself a limit in terms of my involvement. I think I should have also been more explicit with the rest of the team that they should talk to me very openly. Looking back I think that the right thing to do in this situation is to get involved the first time, set clear expectations, and let the employee go if they go back to their bad habits.