Pros
The Orange logo will look great on your CV The company is so big and chaotic it might be possible to hide in a corner and just draw your salary each month. You will find some great people there. The company is trying to create a good working environment, but at the moment, this has only been very selectively applied.
Cons
A serious lack of digital skills or understanding at senior levels. A chaotic and complex company. Lots of deadwood employees with out-of-date skills. Too many people in jobs they are not talented or skilled enough to actually to do. The IT is terrible - four year old cheapo laptops that were obsolete even when bought in four years ago! A mish-mash of unintegrated and out of date internal systems. They talk the talk about employee empowerment but in practice, and unless you went to a few select (usually French) colleges and universities, then you're just another brick in the wall. Poor prospects of career advancement due to overstaffing in France (a legacy of the company actually being the old nationalised France Telecom with a thin veneer of Orange branding over the top) It's almost impossible for Orange to cut staff in France hence the deadwood logjam. If you don't work in France, or sales, then your career development will stall at Orange. Lots of people in jobs they have no relevant experience, skills or even aptitude for. Rigid hierarchy, especially on the French side. No salary growth - negotiate hard at the job offer stage as what you start on is what you will be getting for the next decade or more - with only small annual increases. And even these have been eroded by a deliberate policy of artificially scoring people down in their reviews - thus lowering the value of their bonus. A manager can no longer score an employee above a certain performance grade anymore, regardless of their actual performance.