Apple uses many languages internally. And swift & objective-c are very close in programming models in many ways. It's pretty natural for an ObjC dev to learn s

Apple uses many languages internally. And swift & objective-c are very close in programming models in many ways. It's pretty natural for an ObjC dev to learn swift and vice versa I would imagine. If apple is having a hard time find new objective-c dev, but has swift devs, it will just train them. A lot of code is in C++ at apple, like most of their graphics, UX & networking. Drivers in C. A lot of apps are non-ARC objective-C still and so on. Also swift is not a solid enough language yet. Debuggers, compiling & indexing are too slow & unstable and there are things like ABI stability that are not delivered yet. I would give swift ~4+ years before it would be something to consider replacing Objective-C completely.