Thorough and efficient. First off was a technical phone interview. The questions ranged from pretty basic, to detailed, specific, more difficult. They don't impose any time limits, and are happy to let you talk through the answers. It's obvious that the interviewers are knowledgeable enough, that they aren't looking for textbook answers (though in some cases I'm sure those would work too).
The next step is the in person interview. Everyone is welcoming, and again no time constraints are imposed. Here they ask some more general questions, to see if you're a good fit for the team culture. There are also more technical questions, some a bit more 'hands on'. Again, they're not looking for perfection, but they'll pose some good challenges to see how you problem solve, along with basic coding skills.
Overall, I found the interview to strike a great balance. It's challenging, but not impossible.