I applied online. The process took 1 week. I interviewed at Citadel in Sep 2019
Interview
Introduction first, and directly start with coding problems. They push you hard to solve a problem till you cannot say a word. Citadel is competitive and high pay in the industry, though the turnover rate is high.
I applied through a recruiter. The process took 4 weeks. I interviewed at Citadel (Chicago, IL) in Dec 2019
Interview
Basic phone interview followed by 4 hour in person interviews with 4 different people from department. Not much info was given about the actual job which made interview process difficult. One interviewer was only interested in mocking resume and what he would change.