Pros
I feel so lucky to be working at Flatiron as my first software engineering job out of college. At Flatiron, I've found a tremendously supportive culture, which coupled with the great intelligence of the employees, makes for excellent learning opportunities. It is also great to work on such important problems at Flatiron, and know that that is important to every member of the company. Overall, I've been so happy with my experience at Flatiron.
Cons
Hmmm, I suppose for someone who is used to/wanted to work at a very large company (i.e. Google, Microsoft), there may be certain aspects of Flatiron that might not be what they hoped for just due to the size and age of Flatiron. But I also feel like Flatiron's size and growth offers a lot of new opportunities and benefits. So really just depends on what you're looking for.