I believe I completed a phone screen (with online pair programming) followed by five in-person interviews; four of these involved pair programming. I'm quite senior and happen to be very good at solving interview programming questions, so I essentially breezed through the coding. Really, these interviews boil down to just two things:

1. How well can you solve problems and write code?
2. How well do you get along with your interviewer?

Even if the recruiter tells you otherwise, I STRONGLY recommend you show up with your own laptop and ask your interviewer if you can use it. Have your preferred programming environment completely set up and ready to go. Working in an environment you are very comfortable in will do wonders for your coding and gives your interviewer a chance to see you operating on all cylinders.

I have a question involving DFAs and NFAs.