Apple

Apple

Posted via Apple Careers

Darwin Runtime Engineer, Core OS

Always Hiring

Posted Aug 26, 2026

Role at a glance

Salary
$129.3K – $225.3K/yr
Location
Cupertino, California, United States
Work arrangement
On-site
Employment
Full-time
Education
Master's

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About the role

Original posting provided by Apple

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Summary

For the engineer who obsesses over the butterfly effect of a single line of code, there is no greater stage than Apple's Core OS! Core OS builds uncompromising, lightning-fast foundation that iOS, macOS, watchOS, tvOS, and visionOS stand upon. We don't just write software; we forge the soul of the machine, ensuring the operating system and the hardware breathe as one to create a seamless device identity.

At the center of it all is Darwin, the UNIX-like heartbeat of Apple's operating systems, spanning from the deepest levels of the kernel up through critical low-level user components. The Darwin Runtime team is seeking visionary engineers to push the boundaries of low-level system technologies. If you obsess over performance, security, and the massive cascading impact of your code, your life's best work is waiting for you here!

Description

The Darwin Runtime team is responsible for the development and evolution of low-level user space libraries such as Grand Central Dispatch (GCD), Inter-Process Communication (IPC) technologies like XPC, pthread, and malloc, among others. The foundational libraries built by our team are the invisible engines powering the iPhone, iPad, Mac, Apple Watch, Apple TV, and the groundbreaking Vision Pro. We want an engineer with the drive to operate autonomously, the hunger to master new domains, and the ambition to step into technical leadership. Here, your voice shapes the future. You will drive critical design discussions, elevate peers through code reviews, and push the boundaries across a spectrum of technologies. Our environment fosters a culture of deep technical innovation, massive autonomy, and true ownership.

Responsibilities

Design and implement new features and APIs for Darwin Runtime technologies like GCD, XPC, pthread, and malloc, among others
Develop and maintain high-performance runtime libraries that handle 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
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
Write unit and integration tests for new and existing code
Work with cross functional teams to enable developer and product requirements

Minimum Qualifications

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
BS or MS in Computer Science or equivalent degree

Preferred Qualifications

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
Experience using Gen AI tools for Software Development

Pay & Benefits — Cupertino, California, United States

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 $129,300 and $225,300, 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.

Application Deadline

Apple accepts applications to this posting on an ongoing basis.

Apple

About the company

Apple

Large Enterprise

Apple Inc. is a global technology company known for its innovative products and services, including the iPhone, iPad, Mac computers, and Apple Watch. Founded in 1976, Apple has continuously pushed the boundaries of design and functionality, earning a reputation for high-quality consumer electronics and software solutions like iOS and macOS. With a strong commitment to user experience and privacy, Apple also leads in digital services, offering platforms such as the App Store, Apple Music, and iCloud. The company's focus on sustainability and corporate responsibility further enhances its standing as a leader in the technology sector.