A C++ developer’s role is to design and maintain desktop and mobile applications. They will meet with the product’s stakeholders to discuss their development requirements, budget, design standards, etc. Then they will design a development strategy based on the clients’ requirements.
Since C++ is mainly used for backend development, you’ll likely have to work with front end engineers unless you know other front end programming languages. C++ is very popular in mobile app development and is suitable for Android and iOS. However, it is a native iOS programming language, whereas, with Android, you can only re-use your C++ libraries.