I found so many different questions that were similar to what I'm asking, but none that were quite the same. I was invited to come to an in-person interview tomorrow morning in San Francisco for an software developer position.

I've never actually gone through such an extreme vetting process, so I'm not sure what to expect next. I would love some advice, so please let me explain what I've experienced up to this point.

1) Initial phone screen with HR person. This was a friendly, non-technical phone interview that went really well. After about 20-30 minutes they invited me to participate in a "coding challenge". I accepted and was emailed instructions.

2) Coding Challenge - this was the most intricate, detailed coding challenge I've ever taken part in for employment. I'm used to 30min timed tests on HackerRank, or a request to build a basic app. This was way more involved. I was asked to build a decent sized app to the best of my ability within 48 hours. I literally worked on it for about 44 hours, only stopping to sleep for four hours. This is a dream job for me so I performed this to the best of my ability, pulled out all the bells and whistles, and knocked it out of the park.

3) Technical Phone Interview - they were impressed with the app I made for their code challenge, so they scheduled a one hour technical interview over the phone a few days later. This was also the most grueling technical interview I've had. Not only did they ask me about some very advanced concepts regarding the language I work with, but even asked me to walk them through my process for writing unit-tests and designing data models, etc. All and all, aside from a little bit of a language barrier and having to ask the interviewer to repeat his question a couple times it went very well.

4) In-person Interview - This is what I'm going to tomorrow. I would like to know what to possibly expect so I can prepare myself to the best of my ability. I know that nobody can know for sure, and every company does things differently, but if anyone can even share their experiences it would help immensely. I feel like I've proven my technical ability to perform this job. That shouldn't be in question any longer...but then again, they may still want to see how I code in person - and not just with a team, but with *their team*. 

I have about 24 hours left before the interview, and want to be continuously preparing myself. Would my time be best spent practicing writing code on a whiteboard, or reading books about Agile Methodologies? Or should I just be focusing on those typical personality questions like "Describe your greatest weakness, and how you work to overcome it on a daily basis."? I'm sure anyone who has been in this position can appreciate the anxiety I'm experiencing over it!

If there's an answer on here I missed that covers this problem exactly, let me know and I'd be happy to remove this question. Until then, I really do appreciate any advice, and/or experience!