First Round was a set of two behavioral interviews conducted on campus at UIUC. I was interviewed by two different interviewers for roughly 20-30 mins each.
Second round was a technical interview where I was emailed a prompt and had a week to conduct an analysis and create a presentation to show my findings.
Third round was in the TTD office, where they showed us around the office and then there were two behavioral interviews conducted by two different interviewers, each 30 mins.