I had my N400 interview today and it was a combo interview. My spouse and I were called in and they started with ROC interview. The officer asked us basic questions like when did my spouse became a citizen, where does he work, where did we get married, did we take any trips after the wedding, did you bring any additional joint documents apart from the ones already submitted. The ROC part lasted for 15 min and then he moved on to the N400 interview, which was very easy. Straightforward questions - civics test, English test, application, that's it. He said that he cannot make a decision now because for combo interviews they need to talk to supervisor to approve but he didn't find any issues with my case. Awaiting oath ceremony letter now. Thanks to this group for all the help!!