A Mac Apps developer designs, codes, and modifies applications for Apple's macOS, according to client specifications. They utilize programming languages like Swift and Objective-C, and tools such as Xcode, to create user-friendly interfaces and high-performance applications. Their tasks include writing clean, maintainable code, debugging, and improving application performance. They also ensure the app's compatibility with different macOS versions and devices. They work closely with UX/UI designers for visual aspects, and often collaborate with other developers and stakeholders. They also test, document, and deploy apps, while continuously updating them to incorporate user feedback and new features.