Pros
Work in music could be great. You have "Deezer sessions" in the same building where you can watch great artists, you are surrounded by music, so it's a nice industry. Deezer has a big website and it's a known brand. People are nice, the place is awesome (garden, large kitchen, and many paintings on walls). Developpers ship features every week, it's product-oriented.
Cons
Deezer is a big company. Many many things are wrong in their codebase but you are not allowed to fix this. You have to ship features, not maintain or increment quality of codebase. Maybe someone higher in hierarchy will allow you to make something. It takes about 2-3 weeks, because, you know, XXX is not sure about this. Yes XXX is not a developer, but you know, he's the boss. Deezer has same problems as big company. Developper are not there to enhance quality or think their codebase, they are here to ship features. When I worked there, the codebase was ugly. 3 functions for the same thing, no micro-service, ... And you can't do anything about this, Deezer is in an industry where they need to ship features against company like Microsoft, Apple or Spotify. No time for quality. That's a choice, but it wasn't mine.