I have been working at Black Mountain Systems full-time
Great people, great work, great transparency
Can be hectic at times, but sometimes that is actually a pro. You'll always have work to do at BMS
The process took a week. I interviewed at Black Mountain Systems (San Diego, CA) in June 2011.
The phone interview took about an hour and consisted of the entire development team (3 at the time) who all asked questions about design patterns, OO design, database design, agile development methods, and data structures.
The second phase consisted of an in-person interview where they give you a programming test where you will have to create a design for a database and implement a business scenario using C#.
The third phase consisted of going out to a local restaurant with the entire team to see if your personality fits in with the team.
The development team is very good and they were asking very challenging questions and the programming test was difficult but fair. It took me about 3.5 hours. It's a super casual atmosphere there they have beers stacked in the fridge. Because of the super casual atmosphere I think I was a bit too relaxed during my third interview and they might have interpreted that as I would be a difficult person to work with. So to any prospective employee remember that even though you are drinking a beers with them you still have to phrase your answers so that they won't offend anybody.