Darwin Runtime Engineer, Core OS

The Darwin Runtime team is responsible for building the low-level runtime technologies like Grand Central Dispatch (GCD), secure inter-process communication systems, memory allocator, threading library, and concurrency and synchronization primitives. The team operates at the intersection of operating systems, programming language design, systems security, and high-performance computing. As a Software Engineer on the team, you'll work closely with kernel engineers, security architects, and framework developers to deliver foundational technologies that enable Apple's next-generation computing platforms.The ideal candidate should be self-motivated and effective in operating independently, with a desire to learn and develop technical leadership. Team members are welcome and encouraged to participate in design discussions, code reviews, and development across multiple technologies. Our environment fosters technical innovation, meaningful technology ownership, and a liberating amount of autonomy!

You will be responsible for working on a range of technologies that form the foundation of Apple’s operating systems. The work would include responsibilities such as:
Design and implement new features and APIs for Darwin Runtime technologies like GCD, XPC, pthread, and malloc
Design and implement IDL compiler frontend and backend systems, including lexical analysis, parsing, semantic analysis, and code generation for both C and Swift targets
Develop and maintain high-performance runtime libraries that handle secure communication, memory management, and component lifecycle across different execution environments
Optimize code generation, runtime performance, and memory usage to meet strict performance requirements for low-level systems
An engineer in the Secure Runtime team would regularly:
Participate in all phases of software development cycle: from problem definition and design, through implementation, testing, and debugging
Diagnose and resolve issues across different layers of the stack
Work with cross functional teams to enable developer and product requirements

BS or MS in Computer Science or equivalent degree
0-3+ years of relevant industry experience in low level systems programming
Passion for low-level system technologies
Fluency in the C programming language
Experience with UNIX-like systems
System design and architecture skills
Strong understanding of operating system fundamentals like threading, synchronization primitives, inter-process communication, scheduling, and virtual memory
Excellent collaborative skills, with the ability to work with a team to design system architecture

Experience with compiler design, including lexical analysis, parsing, semantic analysis, and code generation
Knowledge of capability-based security models, sandboxing, and secure IPC mechanisms
Knowledge of operating system implementation, hardware architecture and assembly programming
Knowledge of Swift or Objective-C
Skilled at interface and/or API design
Experience with lldb or gdb

The people here at Apple don’t just build products, we build the kind of wonder that revolutionise entire industries. Imagine what you could do here! Do you have a passion for understanding how each line of code affects all the others? In the Core Operating Systems group ensuring the OS is inseparable from each device’s identity as a whole. That’s because this group is committed to building fully integrated operating systems that combine hardware, software, and apps into a single Apple experience. Your dedication to cross-disciplinary collaboration will help develop groundbreaking technologies, such as iOS, macOS, watchOS, and tvOS. By crafting these distinct, complete user experiences, you’ll continue to uphold and advance the excellence people expect from Apple devices! The Darwin Runtime team in Core OS is looking for enthusiastic engineers interested in developing low-level system technologies for Apple’s operating systems.

At Apple, base pay is one part of our total compensation package and is determined within a range. This provides the opportunity to progress as you grow and develop within a role. The base pay range for this role is between $126,800 and $220,900, and your base pay will depend on your skills, qualifications, experience, and location.

Apple employees also have the opportunity to become an Apple shareholder through participation in Apple’s discretionary employee stock programs. Apple employees are eligible for discretionary restricted stock unit awards, and can purchase Apple stock at a discount if voluntarily participating in Apple’s Employee Stock Purchase Plan. You’ll also receive benefits including: Comprehensive medical and dental coverage, retirement benefits, a range of discounted products and free services, and for formal education related to advancing your career at Apple, reimbursement for certain educational expenses — including tuition. Additionally, this role might be eligible for discretionary bonuses or commission payments as well as relocation. Learn more about Apple Benefits

Note: Apple benefit, compensation and employee stock programs are subject to eligibility requirements and other terms of the applicable plan or program.

Apple is an equal opportunity employer that is committed to inclusion and diversity. We seek to promote equal opportunity for all applicants without regard to race, color, religion, sex, sexual orientation, gender identity, national origin, disability, Veteran status, or other legally protected characteristics. Learn more about your EEO rights as an applicant

At Apple, we believe accessibility is a fundamental human right. You’ll find that idea reflected in everything here — in our culture, our benefits and our digital tools. By welcoming as many perspectives as possible, we help you build a career where you feel like you belong.

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Apple accepts applications to this posting on an ongoing basis.