OS Kernel Engineer

Apple

Apple

Cupertino, CA, USA

USD 126,800-220,900 / year + Equity

Posted on May 14, 2026
The Darwin Scheduler team within Apple's OS organization is responsible for delivering a high-quality and performant kernel that powers every Apple product — from Apple Watch on your wrist, to iPhone in your pocket, to the Mac driving the creative industry. We work on foundational technology areas such as CPU scheduling, power management, and threading models that are central to everyday life for billions of people. We are looking for a talented new graduate or junior engineer to join us and contribute to the next generation of Apple's operating system. As a member of a small, technically integrated team, you will have a unique opportunity to influence the entire stack — from silicon behavior to user experience — on the world's most advanced and widely used devices.
As a junior OS Kernel Engineer on the Darwin Scheduler team, you will work alongside experienced engineers to learn, contribute, and grow your skills in low-level systems programming. You will be supported through mentorship and paired work as you begin to take on real-world kernel engineering challenges across Apple's platforms. This is an exceptional opportunity for someone who is passionate about systems software, eager to understand how hardware and software interact, and excited to write code that runs on hundreds of millions of devices.
  • Learn and Contribute to Scheduling Policies: Assist in developing and validating CPU scheduling policies that balance performance with power efficiency across Apple's product lines.
  • Performance Analysis: Work with senior engineers to analyze system performance, identify bottlenecks, and understand tradeoffs between hardware capabilities and OS behavior.
  • Cross-Platform Development: Contribute to shared scheduling concepts and code that run across iOS, macOS, watchOS, and tvOS, learning how a unified kernel serves vastly different device classes.
  • Tooling and Benchmarking: Help build and maintain benchmarks and diagnostic tools used to validate scheduler behavior and support engineering decisions.
  • Workload Management: Participate in the design and implementation of features that manage diverse workloads to maximize responsiveness and efficiency.
  • Debugging and Investigation: Learn to diagnose and resolve concurrency and scheduling issues under the guidance of experienced engineers.
  • Collaboration: Work closely with hardware and silicon teams, contributing to the cross-functional work that makes Apple's vertical integration a competitive advantage.
  • BS in Computer Science, Computer Engineering, Electrical Engineering, or equivalent (graduating or recently graduated)
  • Coursework or project experience in operating systems, systems programming, or computer architecture
  • Proficiency in C and/or C++
  • Solid understanding of fundamental computer science concepts: data structures, algorithms, and memory management
  • Strong analytical and problem-solving skills
  • Eagerness to learn and ability to ramp up quickly on complex technical topics
  • MS or PhD in Computer Science or a related field
  • Coursework or hands-on experience with OS internals, scheduling algorithms, or concurrency
  • Familiarity with SMP (symmetric multiprocessing), threading models, or lock-free data structures
  • Experience with performance profiling tools or low-level debugging
  • Contributions to open-source OS or systems projects
  • Internship or research experience in systems software