First call with the HR to better understand the position, the company and see if you fit in the position. Second call with the CSM team, we talked about the position and the company, but of course about you, they are trying to better understand who you really are and if there is a good feeling between the team members and you. Third call is with your direct manager (in office or remotely), she/he is looking for your understanding about the position you're applying for.