After talking with the recruiter, I was set up for a technical screening call with someone on the team I would be joining. It was about 1 hour, and the questions were pretty easy.
They then brought me in on-site. There were 4 rounds of technical interviews (team lead, 2 devs, and a DB guy), followed by another round with a project manager suit. I was provided with a schedule of who I'd be talking to, but it turns out that changed by the time I arrived. The team lead was kind of abrasive, and didn't seem like someone I'd want to work with. The two devs were cool, and asked bigger questions, so each of those sessions was more like an hour-long technical discussion. The DB guy was very cool, but disappointed I didn't know DB stuff (hey, it's not on my resume for a reason!). The suit wanted to talk through a real-world scenario, to discover how I would handle a development schedule.
The recruiting team was good EXCEPT for the recruiter himself. Despite seeking me out, he was constantly late with email replies. I did see him during the on-site interview, and asked him some questions about the business generally. It mostly went like this:
Me: Is the company pre-profit?
Him: Like, the charts they showed us, the revenue's going up like crazy...
Me: What's the biggest challenge facing AppNexus?
Him: Oh, it's like, everything is just so.... awesome...
After the on-site, I didn't hear from him again. Not yet sure if that's a good thing or a bad thing.
I was reimbursed for my travel expenses.