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# Darwin Runtime Engineer, Core OS

- **Company:** Apple Inc.
- **Location:** Cupertino, CA, United States
- **Contract:** Permanent contract
- **Skills:** Apple Watch, C (Programming Language), Artificial Intelligence, Macintosh Computers, Apple IOS, Apple Mac Systems, Apple TV, Assembly Language, Unix, Code Review, Inter-Process Communication, Software Engineering, Virtual Memory, Information Technology, Api Design, Objective C++
- **Published:** August 28, 2026
- **Apply:** https://www.techcareers.com/job.asp?id=3367837489&tx=FK5956FFI&pt=1&aff=0B19D771-A501-4A5E-8338-2A822B784D54&utm_source=Job%20Feed&utm_medium=textkernel&utm_campaign=DE&utm_term=0B19D771-A501-4A5E-8338-2A822B784D54

## About the Role

* 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, * 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

## Description

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., 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.


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