There were three steps to the interview process: a very short phone interview with the technical recruiter, a technical exam/interview with a tech lead in the company, and a final face to face interview with the regional director. The tech interview was the most difficult, but they will tell you a few days in advance what to study for (which was very helpful). It's all written in paper (no whiteboard coding) and you get to solve the problems alone rather than in front of people. They don't care what language you use since you will be discussing your answers to their questions with the tech leads later, so you have enough time to prepare. It's more of a discussion as you go through your answers, rather than a formal interview. I recommend applying here just for this step - the interviewers for this part are smart but forgiving, and you'll walk away having learned something new.
It was a good interview process - not too long, had enough time to get to know the company. Except for the phone interview, you do everything in their office so you get to see the day to day work in person, and they'll give you free food from the pantry afterwards.
You can really tell from the interview that the people there were smart and valued the company culture they were building.