I applied via referral and was contacted the next day to set up an HR interview. The HR rep was very kind and relaxed, and mainly discussed the specifics of working in the Seattle office (mainly, that hours are 3 PM to 11 PM -- apparently this is a dealbreaker for a lot of potential candidates), rather than asking me questions. After this, I was asked to do another interview with a project manager who asked more Dataminr and Twitter-specific questions. They then asked me to do a language assessment, which I declined to complete as I received a grad school offer that more closely aligned with my career goals. I was pleased with the whole process and would definitely apply again after grad school.