Not all of them. Sony designs/manufactures some (known as the Sony FE and E lines) and Zeiss designs/manufactures some (Zeiss Batis, Loxia, and Touit lines).
To make this even more confusing, some are designed by Zeiss but manufactured by Sony and carry both of their logos (nicknamed Zony; e.g., Sony Zeiss Sonnar T* FE 55mm f1.8)
To make this even more confusing, some are designed by Zeiss but manufactured by Sony and carry both of their logos (nicknamed Zony; e.g., Sony Zeiss Sonnar T* FE 55mm f1.8)