We're looking for a Senior mac OS Internals Lead Engineer to drive the development of low-level security and compatibility functionality. You will lead a team of exceptional engineers while remaining deeply hands-on—writing code, reverse engineering OS behavior, and directly owning key system-level components.
Your team's mission is to expand mac OS application compatibility and harden endpoint security by deeply understanding and integrating with mac OS internals. This role is adecuado for someone who thrives on technical challenges, understands mac OS at a deep level, is not afraid of reverse engineering and can mentor others while shipping production code.
What You Will Do:
Design and implement security features using mac OS frameworks such as Endpoint Security and Network Extensions
Reverse engineer mac OS internals and application interactions to enhance product compatibility and security
Develop, debug, and optimize complex system-level code in C++, Swift, and Objective-C, adhering to secure coding best practices
Investigate and resolve issues related to mac OS system extensions, launch services, XPC, and sandboxing
Act as a force multiplier by reviewing team designs and code, offering architectural direction, and coaching team members on best practices
Document technical findings, architectural designs, and implementation details
Collaborate with QA, product,



and support teams to ensure high-quality, secure, and testable deliverables
Stay updated on mac OS updates and security mechanisms in order to inform development
Requirements:
7+ years of systems programming experience with a focus on mac OS internals, frameworks, and security
Proven track record of delivering complex mac OS features to productions with hands on coding in C++, Swift, Objective-C
Deep expertise in mac OS frameworks, including Endpoint Security, Network Extensions, Accessibility, Launch Services, File Providers, daemons, XPC and FSEvents
Advanced skills in reverse engineering Mac OS components using tools like Ghidra, Frida, IDA, Hopper, lldb or other tools of your choice. You're not afraid to look at XNU sources
Strong understanding of mac OS security mechanisms, including TCC, SIP, Gatekeeper
Experience with debugging complex architectures on Mac OS (system extensions, endpoint security, network extensions, launch services, XPC)
Ability to produce high-quality, testable, maintainable and secure code
Nice to have:
Expertise with Network Extensions, Driver Kit, network protocols, proxies
Expertise with APFS, file system internals
C# /. Net experience is a plus
Benefits: Salary: $10,000 - $15,000 USD /month + Holidays
Unlimited PTO

📌 Senior macos internals lead engineer (Heroica Puebla de Zaragoza)
🏢 Sur Global
📍 Heroica Puebla de Zaragoza