During these interviews, I never saw any questions about technical skills or knowledge. If you make it to the interview, they know you meet the technical qualification. What distinguishes one big four company to another is its people. So in addition to being smart, you need to be personable and able to communicate comfortably in stressful moments. Some of the partners like to ask random questions about failures or difficulties you encountered to gauge how you work under pressure. Aside from that, its fairly routine.
