Was flown to NY, had a 3-4 hour interview with more than 5 people. Been in the industry a few years already, and the questions ranged from the pretty easy to the impossibly hard. As a general rule, if it's on your resume, they're expecting you to know the material cold. Bonus points for being able to explain the material coherently. If it's not on your resume, they didn't seem to get bothered when replying that you weren't sure. While this was the most difficult interview I've ever had, it definitely wasn't easy. The interviewers all seemed to genuinely love working for Goldman, and honestly acknowledged the workload is not as easy as a 9-5, which was a big sell to me. Seemed that all the interviewers genuinely loved working with their coworkers, which is something I had never seen before.