Especially for those international students in Germany applying for consulting opportunities, have you done most of your interviews/cases in German or English? I was offered an interview at one of the MBB's, and although client work is mostly in English they said that the entire interview (1 personal CV check, 2 cases) would be conducted in German
Interview language for German-based internships?
German. They will test English but fluency in German is must for new hires because clients might want documents in English but second level executives and management are still more comfortable in german than in English. Therefore german fluency is key to build rapport with them.
in Germany you may get cases in both English and German, but the majority will be in German. To my knowledge, every office in Europe requires local language knowledge besides English, with the exception of the Netherlands and the Nordics where knowledge of English only would be fine.
Based on a sample of my students, the interviews at German MBBs are in both languages, so you should be confident with German as well