Pros
People are very welcoming and make you feel very comfortable with the onboarding. The company contains lots of documents and videos in order to explain about the business as a whole, like its history, its customers, success cases, etc., so you don't have any difficulties to understand what your work is related with. The have lots of big customers, and its product is very nice and big, being able to use in a lot of different ways, something that makes you feel proud of being part of.
Cons
The only negative that I would say is just related with the technical side, where there are lots of tools that are not standard. It was built internally by the company, so the learning curve in order to become productive tends to be slower than a project that uses standard tools to do the things. Also, since there are tools built internally, some are documented (very well documented by the way) and some are not, so you need to look for the knowledge through the team.