Pros
If you're unsure about what you want to do and are curious about a lot of different areas, Catchafire is a good place to explore. But, you must first prove that you're able to succeed at your given task. Do your job, do it well, be clear about what you want next and vocalize it. It's also a smart & hardworking team that's supportive of every team member. Because of the size, everyone cares a whole lot about you as a person, personally and professionally.
Cons
With any start-up, hours are sometimes brutal. There's always more work to do than the day allows but the team is efficient and constantly works to optimize. Change also happens all the time-- you can be working on one model one week and be expected to adopt a whole different model the next.