I applied online. The process took 3 days. I interviewed at Susquehanna International Group (Phila, PA) in Sep 2018
Interview
First, human resources phone interview. Second step is phone interview with Systems or Engineering team member. If they comfortable with your expertise you will be offered an on-site interview with different engineering teams and a HR specialist.
Interview questions [1]
Question 1
I was asked to describe Linux network stack and ways to optimize it for different loads