What is essential for your work? Your team! No matter if you are an introvert or extrovert person - you usually work with other people. Even if you prefer to work alone, there is usually someone besides you. To work effectively, you have to have a strong connection with your future team: your boss, project manager, and other developers. Whoever it will be, you all have to understand each other, rely on each other, and, of course, it is always more pleasant to work with people you like and are familiar with. That is why you suppose to ask the interviewer about your colleagues.
Another critical question connected with the team topic is the organization of the team you will join. Ask how big the team is, who is the part of it, and who is responsible, for what, to whom. Do not forget to ask what your role in the team will be and how the projects are planned. Answers will give you a complete picture of what your work will look like and what you can expect in the future.