I've been a silent visitor in this forum. I sincerely appreciate every single information being shared here. They helped me gain a lot of insights of this looong journey and keep me stay positive. It's my turn to tell my story, and hope at least one person would benefit from it.
Here's my timeline -
PD Jan 2015
I-140 approved July 2016
AOS filed 5/2/2018
Bio completed 6/4/2018
EAD/AP approved late July 2018 (I still haven't received the card, I called and they told me to wait..)
Interview scheduled 8/1/18 (received the official letter after several days)
Interview date 9/12/18
I had my interview this past week in NYC. I don't have an attorney with me for the interview. The wait was nearly 3 hours. I checked with the clerk twice and she kept confirming the IO had my case and would call my number when he's ready for me. So (if you don't have an attorney) I would say bring someone with you if you can, just in case the wait is long and you need a restroom break. You don't want to miss your name/number. Anyway, 1, 2, 3 hours passed, my number was announced.
The IO was friendly (I think I'm lucky). I took the oath, photo, finger prints (my finger prints didn't match initially >"<, IO ran it again and this time they matched..). Signed the waiver of attorney. Then IO went over / confirmed my status from the date I landed America as an F1 student till now; checked visa stamps, i-797 approval notices (OPT, H1b, EAD/AP). Questions asked: where did you go to school, what did you study, are you working at the company who sponsors you, what's your current job title, what's your job responsibilities, how do you like your company, how many people work in the same role at your company. He took notes along the way and went over everything I submitted with the AOS application, make sure he has everything. He kept only my employment letter, copies of EAD/AP approval notices, latest h1b approval notice, driver's license, and passport. He didn't ask for birth certificate, tax return, W-2, paystub, diploma at all.. (I did submit copies of those with AOS thou). And then we went thru all the Y/N questions. The interview took about 45 mins.
At the end, he said he had everything he needed, and "you did a fantastic job" (I must say that sentence totally lifted the cloud in my heart). He then explained that normally he would be the one to make a decision and just "boom" (he made a stamping and tapping on the keyboard gesture), but because they ran out of visas this year so he couldn't make a decision on my case, and my case will be in a continuous status. My case and all other cases with interview completed during back log will be sent back to the service center, and the staffs there will process the final decision when there are visas available again. They will perform some administrative steps and check all the docs again and if none of the forms expire, they will approve the case and I will receive an approval notice, followed by the physical GC. He told me to cross my finger and to give probably 90 days, and if I don't hear anything call the inquiry number.
PS: online status no update yet
I would say, just be prepared (even over prepared), confident and truthful during the interview. I made an error on my i-485 and I explained it to the IO and it was an oversight on my part. He just corrected it on the spot without any problem. Now I just need to be patient and hopeful I can hear the good news soon, and I wish everyone all the best and bunch of luck on your GC journey!