I had to talk to the department and wait for their decision. After some paperwork, I could meet them. We had a conversation about my skill sets and my working hours and status.

Background check on your academics, and interests. Ask about the the projects that you have done so far and also ask if you have any questions. And we ended with some more chatting about the future.

I was interviewing for TA position in the psych and brain sciences dept. First I reached out to the department assistant that I found on the website. I mailed them continuously for a few weeks. Once the position opened he forwarded my resume to the professor who then interviewed me. Before this, I also had to prepare a PPT on any topic and give a short lecture to prove my English fluency.