How common is it to switch departments or teams at Globant?

Well if you are talking about becoming from QA to Dev as an example, is pretty complicated you need to have the knowledge of the position you are willing to fill and also your salary should be less or equal if is greater than the position you want to fill well is kind of complicated so you need to fill the same knowledge of the position you want and the salary should be less or equal no greater.

It's quite common. You can be assigned to several projects along the year. Of course it depends on the projects you are assigned. I've been in the same project for 18 months but some of my colleages have been in 5 proyects during the same period. You can also change your "studio" let's say from backend developer to test automation engineer or data-science, but it requires you to prove your knowledge and approval by yor mentor

depends on the project. I have been in the same team for last 3+ years