Pros
CloudFlare is an ambitious vision from the founding team, paired with a smart team able to deliver on it. This combination has made a significant impact on the Internet landscape. (all your glassdoor bytes actually transit through their product!) The company itself is very engineering and data driven, and everyone feels personally involved in making a better Internet. The CEO has done a tremendous job at establishing CloudFlare as a brand that is impossible to ignore. There are still a lot of interesting technical challenges to solve. Get a job at CloudFlare if you want to apply yourself on something big in a no-BS environment!
Cons
The organization is all flat and self-managed in a sense, that's laudable. However some people are more "in the know" and close to the execs than some others, which makes it a bit confusing. At times it seems like the immediate story is more important than a big picture solution. But overall things seem to always move in the right direction.