Pros
You work to bring music to people, which is a laudable work. You get everything you need to do your job, at very good office spaces. There is 100% transparency in what the goals for the company are, and what decisions are being taken to reach them.
Cons
Spotify is not the disruptive product that once was, and it is not that special anymore. While growing, it's becoming slow to innovate and come up with new features. The company is very focused on products and often forgets about the technical side of the things. The structure of the organization in small teams is both a blessing and a curse. There is a lot of duplicated work going on simultaneously, product of the lack of communication between teams working in similar tasks across the company. The small multifunctional teams makes it difficult for someone to excel technically, since every member needs to be flexible enough to work in different areas.