The first interview was a half hour phone call. The next step is an hour long panel interview with three employees. If you're still a college student and/or don't have much experience in finance or accounting, this interview may be very difficult. They ask a lot of very specific questions about the industry. The rest is going through your resume very thoroughly and if it's on your resume, be an expert at it to know how to answer any questions. They also asked for several examples of what you could've done better and things you didn't do well.
To sum it up, all the interviewers were friendly and helpful. The follow up was also very timely. Just know that they're basically hiring for an entry-level job and they will do some training, but the interview process seems to expect you already have a lot of knowledge.