I was referred by an internal employee and received a call within few weeks for a telephonic interview. After a brief telephonic interview with HR I was asked to come in for an on-site interview with manager, director and finally by VP of Operations and back to Director of HR. The entire hiring process took around 3-5 months which was mostly waiting for an official offer. Salary offer was tied to current compensation at old employer. Normally there's minimum room for negotiation. Otherwise, easy and direct questions. No case studies or in-depth cross questioning. As long as you can speak off your resume you should be fine.