I applied in-person. The process took 1 day. I interviewed at Columbia University in May 2018
Easy interview
Application
The process took 2 days. I interviewed at Columbia University in Mar 2009
Interview
It was a casual and easy experience. During the first day, I gave a presentation about what I did during my phd, followed by QnA. Then I was assigned to talk to each postdocs in the lab. Especially the ones in the area that I'm interested in. Got home, wrote a thank-you letter to the PI and express that I'm interested in working there. And got invitation of 2nd interview right away. This time I was mainly talking with the group that I will be working in. At the end of the day, the PI has offered me the job!
The interview was pretty easy which is common for a postdoc. I just had a Skype interview with the professor and then after 1 week or so got the offer.
I applied through college or university. The process took 2 weeks. I interviewed at Columbia University (New York, NY) in Jul 2016
Interview
I was called by my professor and it was one to one interview. I just had to present my previous dissertation work. It was very simple as it was for postdoctoral position. I was just asked questions based on my presentation and topic.
Interview questions [1]
Question 1
Are you interested in pursuing your career further in academics
I send a letter and my resume to the PI saying that I would love to join the group. Got some friendly answer so I went to new york to meet in person. Interview was rather informal, just a short chat with the PI and lunch with the rest of the group.