Small startup environment for a highly successful app that brilliantly serves a niche community. Some very intelligent people there so you will for sure learn how to think and ask the right questions from a software development perspective. You get to see all sides of the software development cycle. Bosses take care of you and are super fun. The company give smany cool opportunities to test the a/b test the app in the wild.
A fast moving environment with order and processes. Work with smart individuals with many years of experience in the industry. Get your code in the hand of hundreds of thousands of users with short release cycles. Everyone's input matters, regardless of seniority.
Desventajas
Lots of remote employees around the globe, which doesn't allow for in person talks... but some people would consider that a pro :)