Four rounds of interviews with a combination of cultural fit and technical knowledge. Technical/coding portions were not too difficult, some basic algorithms and OOP knowledge. It went fairly fast, going through one or two interviews a week and the recruiter was always quick to check in the next day. Interviewers were always on time, nice, and professional.
After the last interview, complete silence. No check in, no feedback of any kind. Considering how on top of things they were, this came as a surprise. At least a rejection email would have been appropriate given all the time involved.