it was mostly asking about past research experience and academic questions to start with. overall it is not very challenging so i think ok. also ask about coursework and some behavioral questions too.
I applied online. The process took 2 weeks. I interviewed at Columbia University in Sept 2022
Interview
You first apply through the columbia website and then you will hear back from them if you get in. Then you move on to the interview. Afterwards, you hear back from them asking for a confirmation on whether you can start working or not.
Interview questions [1]
Question 1
Q: Why do you want to work here? Q: How will you manage your studies and work?