Initially submitted application (with required writing sample of an economics research) through my university's job listings site. Got an offer for phone interview (about 30 min) that asked basic questions about my background, why I'm interested and one general question on antitrust/competition. The first in-person interview was at the office for a total of 2 hours, with 2 analysts and a phD economist, who administers the 45min case study, which u analyze and answer 3 questions (including some spreadsheet work) and present it to the economist. The last interview is also around 2hours with 2 other analysts (who asked some specific regression/stats questions) and some senior staff (VPs etc). Overall the office and culture seemed like a library, with professional and serious staff.