Pros
The thing that stood out most for me at C3 was the professionalism and friendliness of the staff. These are highly motivated people at the top of their game and working with them was a pleasure. The problems they are trying to solve haven't really been attempted before which makes them all the more fun and challenging to work on. For me, having a strong leader is very important to maintaining confidence in the company as a whole and I would say C3 delivers on that front. I always looked forward to Tom Siebel's company updates where he'd gather all the staff and present his thoughts on where the company was now, where it was going and how to get there. They were a valuable insight into the 'big picture' and the Q&A sessions that would often follow were also very helpful. They helped me understand where my work fit into the broader scope, which in turn made it more meaningful and ultimately satisfying. It seemed no expense was spared on the environment, with large open spaces and tasteful decor making it a pleasure to spend time working in. A free breakfast and lunch was provided and there was a full sized pool table and table tennis to help break up the day. Being able to take a stroll by the water front helped to clear the head too. There was also a complimentary gym with a pool and even rock climbing about 2 mins walk from the office, which I enjoyed taking advantage of.
Cons
As with most small companies, there is no well defined career ladder to climb and it's often unclear exactly what it takes to get a promotion. But I'm sure that as the company grows that will be addressed.