I applied online. The process took 1 day. I interviewed at Citadel (Dublin, Dublin)
Interview
After classic screening, I was invited to the onsite interview in Dublin. I should note that I originally applied for a different role, something like quant research position I think, but the recruiter came back to me and redirected me this role as it might fit me better. One thing I really appreciated is that they booked everything to the highest standards. The flight back and forth from London to Dublin were on 1st class seats, and throughout my stay they've booked 5 star hotel in Dublin and fully accommodated for whatever food you've purchased. The interview itself was half mathematics (typical statistics, brain-teaser types) and half options related questions.