I was referred by an old co-worker. I received and email asking me to do an "on demand" video interview. After I submitted that, I received an email asking for 7-25 references. They use an online reference checker where they send an email and ask those references to answer a series of questions. However, regardless of whether your references are a direct supervisor or a fellow coworker, the questions are asked as if they were all supervisors. I then got a face to face interview with the divisional manager. Next step would've been an interview in Chicago with top management.