Tech Lead - MacOS

macOS Systems Engineer / Tech Lead – On-Device AI

Location: USA

Compensation: $275,000–$350,000 base salary + equity

Employment Type: Full-Time

Seniority: Staff / Principal / Technical Lead

About the Opportunity

We are partnering with an ambitious, early-stage AI startup building a new generation of private, personalized AI that runs directly on users' devices.

The company's vision is to create a truly personal AI assistant that understands how individuals work, connects context across their applications and information, and intelligently executes tasks on their behalf, without compromising privacy.

Rather than relying entirely on cloud infrastructure, the team is building sophisticated on-device systems that bring together AI, personal context, memory and native application capabilities.

They are now looking for an exceptional macOS Systems Engineer / Tech Lead to take technical ownership of their macOS platform architecture.

This is a foundational engineering position with significant autonomy, technical authority and the opportunity to architect a complex native Mac application from the ground up.

The Role

As the macOS Systems Engineer / Tech Lead, you will be responsible for designing, building and scaling the underlying systems architecture of the company's native macOS application.

This is not primarily a frontend or UI development position. The focus is on the platform infrastructure beneath the application, including process architecture, background services, inter-process communication, security, resource management and application distribution.

You will serve as the technical lead across macOS engineering, working closely with engineers across Mac and iOS while remaining deeply hands-on with implementation.

You will establish the architectural foundations that other engineers build upon, define engineering standards and take ownership of critical platform decisions.

Key Responsibilities

macOS Architecture & Systems Engineering

• Own the end-to-end architecture of a complex, native, multi-process macOS application.
• Design and implement core platform components, services and frameworks using Swift and Objective-C where appropriate.
• Architect and build XPC services, including secure inter-process communication and code-signature verification.
• Define process boundaries, service interfaces, security models and performance constraints.
• Develop and maintain background services, login items, launch agents and daemons using macOS system frameworks.
• Design appropriate process isolation for resource-intensive components, including local AI models and data processing systems.

Security, Performance & Distribution

• Own application sandboxing, hardened runtime configuration, entitlements, code signing and notarization.
• Lead the technical implementation of Mac App Store and direct-download distribution.
• Build and improve application update mechanisms, continuous integration, crash reporting and release infrastructure.
• Optimize system performance, memory consumption, energy efficiency and application reliability.
• Use profiling and diagnostic tools, including Instruments, to identify and resolve complex systems-level issues.

Technical Leadership

• Establish technical direction and architectural standards for the macOS platform.
• Lead design reviews, code reviews and major technical decisions across the Mac engineering team.
• Collaborate with iOS engineers to ensure architectural consistency and high engineering standards.
• Personally implement critical and technically challenging systems components.
• Mentor engineers and contribute to technical hiring decisions.
• Own release readiness, quality standards and go/no-go recommendations for major application releases.

Required Experience

We are looking for an engineer with deep native macOS systems expertise who has previously taken meaningful architectural ownership of complex applications shipped to real customers.

Essential qualifications:

• 10+ years of professional software engineering experience, including 5+ years working with Swift.
• Proven experience architecting and shipping production native macOS applications using Swift and/or Objective-C.
• Demonstrable ownership of a complex, multi-process macOS application, beyond individual features or UI development.
• Strong experience designing XPC services and secure communication between application processes.
• Hands-on experience with macOS application sandboxing, code signing, notarization, hardened runtime and entitlements.
• Experience distributing production applications through the Mac App Store or directly using Developer ID.
• Familiarity with macOS background execution mechanisms, including launch agents, login items and/or daemons.
• Experience isolating