A friend of mine, who works there, submitted a referral for me. A month or two passed by and then someone from HR contacted me to setup a phone interview. The phone interview wasn't very long, as it served just as an introduction with HR and to setup the next interview with a manager.
The phone interview with a manager was a general interview. He asked me to go over my resume, some questions about my skills and work experiences, and some behavioral questions too. Some of the questions that struct me were: " Tell me your strengths and weaknesses", "What do you fear the most about your current job" and "Tell me about your biggest failure on the job".
Apparently I passed that interview, because I was called for 1:1 interview in person. This one was for about 3 hours, where I met three executives separately, for an hour each. This was more difficult, as they asked me a lot of specific questions about projects, project management, databases, finance, technology, etc.
I would recommend that the candidates are honest and talk about their skills and experiences with a positive tone. For example, if you don't have an experience in something, indicate your willingness to learn and mention how you learned something in the past. For negative questions, such as "What was your biggest failure", the best tactic is to be honest and talk about something that went wrong in your experience, but finish with the steps you took to fix it. Also, research the company before going to the interview and prepare some good questions to ask them, they appreciate that.
They will send you an interview package email before the 1:1 interview, so make sure you read all the links in there. There are some Harvard and Yale Business Cases I found in there and they were very helpful.
For the company culture, I can only tell you what my perceptions are so far (I haven't started working there yet). The people seem very nice and willing to help out. They are also very smart and experienced, so you have what to learn from them. They work on projects for clients and that's what you are paid to do as well. In the current climate, it sounds like clients are pushing them for efficiency, which means do more in less time with less resources, so you need to be ok with that. I imagine there will a lot of days when you work long hours, and there is a lot of travel. Some of the travel is quick, like a day or two, and sometimes you can be asked to work 4 days a week in a different location (like another city) and then come back and work the 5th day from home or in the home office. It seems like they pay well and there are opportunities for advancement, if the client and your co-workers like you, so it seems like a good arrangement to me.