I applied online. I interviewed at Mathematica (Washington, DC) in Oct 2014
Interview
I had a 30-minute phone interview and then an all-day in-office interview with multiple Mathematica employees. Pretty basic questions about your research interests and experiences. They care about both your academic and professional achievements.
Interview questions [1]
Question 1
Questions such as: What are you looking for a in a job? Why are you interested in Mathematica? Describe your research experience.
I applied online. The process took 1 day. I interviewed at Mathematica in Jan 2016
Interview
It was a very general interview. The hiring manager was very curt in the way that she asked questions and she did not make the role seem attractive or interesting. She spend more time talking about the company itself than taking time to get to know me as an interview candidate.