Hi hi fellow AOSers! Yes, I had my interview and there was nothing unexpected thanks to all the contributors here who've posted about their experience. Having chugged a whole Starbucks flat white right before entering the FO, I was super caffeinated, feeling like a #ladyboss in my white blazer that I somehow managed to keep clean during the whole hour-long metro ride to the FO, and American flag tied around my waist (jk). The IO was very calm and professional; it seemed that he was experienced and had worked on DV cases before. After all the formalities, going through the I-485 form, and checking originals of my university diploma, birth certificate, and the DV fee payment receipt, he said he had requested documents from the Department of State and he would then have everything needed to make a decision on my case within the next week.
When I asked whether my background check had been cleared, he laughed and said, "why does everyone ask me that?" lol. He checked his files, saw that I'd done my biometrics only 4 weeks prior to my interview, but that I was clear. He did mention that he would've conducted an interview regardless, so it seems the Fairfax FO may schedule interviews before background checks are cleared.
Anyway, he said I should receive a notice in the mail when my petition is adjudicated, and the Green Card within 1 month from the notice date. Fingers crossed I get approved! Will post a (hopefully happy) update once I hear back.