An AutoLayout developer designs and implements user interfaces for applications on Apple platforms like iOS, macOS, tvOS, and watchOS. They use AutoLayout, a system that creates flexible and responsive layouts, to define rules (constraints) for positioning and sizing UI elements. This ensures the interface adapts to different screen sizes, orientations, and languages. Their responsibilities include coding, debugging, testing, and optimizing the layout code. They collaborate with designers to create visually appealing and user-friendly experiences. They also stay updated with new AutoLayout features and best practices to ensure optimal app performance and responsiveness.