UI Compositing Engineer

Apple's Compositing, Color, and Display Software organization provides the graphics software foundation for all of Apple's innovative products, including iPhone, iPad, Apple TV, Mac and Apple Watch. Our goal is to enable developers and HI designers to create exceptional visual experiences by efficiently utilizing hardware acceleration and color technologies through compositing and display. We're a highly technical team working on critical compositing and windowing system components across Apple's platforms. Our mission is to maintain and evolve the compositing infrastructure that powers billions of devices. We tackle challenging problems in scheduler architecture, event processing, security rendering, hardware integration, and legacy system maintenance while maintaining the high-quality standards our users expect. If you are passionate about building efficient compositing systems, optimizing for new hardware capabilities, and great battery life for millions of users worldwide, we want to hear from you. If you're excited about working across the full spectrum of compositing challenges-from scheduler design to event handling to security features-this role is for you.

Description

We're seeking an exceptional senior software engineer who combines deep technical expertise with versatility and strong leadership to work across our UI Compositing team. You will contribute to the core compositing infrastructure that powers all Apple devices, working on challenges that span from low-level system optimization to cross-platform feature development. This role requires the ability to context-switch between different technical domains while maintaining the same high standards of quality and performance. As part of the UI Compositing team, you will play a central role within our graphics stack. Your work will span multiple areas of compositing infrastructure-optimizing how frames are scheduled and displayed, implementing visual security features, handling user input events, and maintaining critical system code. You'll work on problems that balance performance with battery life, ensure security and privacy, and maintain the reliability of systems that billions of users depend on daily. Partnering with GPU driver teams, Display teams, and Metal framework engineers, you'll help shape compositing infrastructure across iOS, macOS, tvOS, and watchOS. Our team values versatility, deep technical expertise, and a proactive approach to problem-solving. We work in complex Unix-based codebases where autonomy, strong debugging skills, and the willingness to dive deep into intricate system-level code are essential. The ability to move fluidly between different technical challenges and work across the full compositing stack is critical to success in this role.

• Contribute to core compositing infrastructure across multiple technical areas of the team
• Work on performance optimization including frame scheduling and display synchronization across iOS, macOS, tvOS, and watchOS
• Design and implement compositing features that balance visual quality, battery life, and hardware capabilities
• Build system features that ensure security and privacy for users
• Work on input handling and event processing systems
• Maintain and evolve critical system code, balancing modernization with stability and compatibility
• Drive technical decisions on complex cross-platform compositing challenges
• Work with new hardware capabilities including advanced display technologies
• Identify and resolve compositing issues across the codebase through systematic debugging and root cause analysis
• Collaborate with GPU driver teams, Display teams, and Metal framework engineers
• Navigate seamlessly between different Apple platform codebases and technical domains
• Champion clean, maintainable solutions and contribute to knowledge transfer initiatives
• Mentor junior engineers and provide technical guidance across compositing areas

• 5+ years of experience in software development with strong systems programming background
• Deep familiarity with Unix environments, system programming, and low-level debugging
• Proficiency in C/C++/Objective-C with understanding of memory management, threading, and performance optimization
• Strong debugging skills with ability to trace complex issues through multiple layers of abstraction using tools like lldb, dtrace, and Instruments
• Understanding of compositing, frame timing, vsync, and display technologies
• Proven track record of leading technical initiatives and driving projects from concept to completion
• Demonstrated ability to work across multiple technical domains and context-switch effectively
• Self-driven approach to testing, validation, and ensuring code quality
• Demonstrated ability to mentor others and provide technical leadership
• Bachelor's or Master's degree or equivalent in Computer Science or related field

• Experience with compositing systems, scheduler design, or graphics infrastructure
• Knowledge of advanced power management and battery-life analysis techniques
• Experience with GPU coordination, Metal, or modern graphics APIs
• Familiarity with advanced display technologies and variable refresh rate systems
• Understanding of display hardware and GPU architectures
• Experience with event-driven systems and input handling
• Experience working with large legacy codebases and incremental modernization strategies
• Experience working across multiple Apple platforms (iOS, macOS, tvOS, watchOS)
• Track record of architecting cross-platform systems that balance performance, quality, and maintainability
• Experience integrating software with hardware capabilities
• Proven ability to define processes and drive automation to increase productivity
• Experience shipping consumer products at scale and working across hardware and software
• Versatility to work across different technical areas and problem domains