Senior Networking Engineer - Full-Time (40h) - Overlap with Australia Business Hours

Senior Networking Engineer

1. Role Mission

We're seeking a Senior Networking Engineer (Contract) to delivery

expect-level development across our core networking product suite on Windows and macOS.

This role focuses on accelerating key technical milestones within our networking stack,

ensuring system-level implementations are secure, performant, and tightly integrated with

operating system frameworks.

This engagement is delivery focused. Success in this role is measured by the quality, stability,

and production readiness of technical deliverables, as well as the smooth integration of new

components into the existing platform.

The ideal candidate brings deep experience with OS-level networking APIs, system extensions,

and high performance networking architecture, and can quickly contribute within an

established engineering environment.

2. Engagement Model: "Project-Based Delivery"

This contract engagement centers on executing defined technical initiatives within our company's

networking platform.

Areas of Focus:

● System Extension Development: Develop and maintain macOS System Extensions

using the NetworkExtension framework in Swift and implement Windows Filtering

Platform (WFP) callout drivers using C++ or C#.

● Core Networking Engine Integration: Enhance and optimize the platform’s high

performance networking engine written in Go, ensuring reliable interoperability with

platform specific system hooks.

● Interprocess Communication and Service Orchestration: Design and implement

secure IPC mechanisms to connect privileged services with user space applications,

including:

○ XPC on MacOS

○ ALPC, Named Pipes, or gRPC on Windows

● Performance Optimization: Diagnose and resolve networking performance issues

including packet path bottlenecks, memory leaks in long running services, and

operating system specific connectivity edge cases.

How You Will Work

● Subject Matter Expert (SME): Serve as a system-level networking specialist with deep

knowledge of Windows and macOS networking APIs, operating with minimal ramp-up

or oversight.

● Hands-On Development: Spend ~80-90% of your time actively contributing to the

codebase, translating architectural requirements into production-ready

implementations.

● Technical Quality and Standards: Follow our company's engineering standards for memory

safety, concurrency management, code quality, and documentation to ensure

maintainability beyond the contract period.

3. Key Responsibilities

● Platform Implementation:

○ Delivering feature-complete implementations for macOS

NEPacketTunnelProvider (Swift) and Windows WFP callout drivers (C++).

○ Integrate platform-specific networking logic with shared Go services.

● Cross-Language Integration:

○ Implement and maintain safe interoperability between Go and platform-specific

system code using cgo.

○ Ensure reliable and efficient data exchange across language boundaries.

● System Reliability:

○ Troubleshoot and resolve OS-level networking challenges including:

■ Sleep and wake reconnection logic

■ DNS interception conflicts

■ VPN kill-switch enforcement

■ Long running daemon stability

● Release Readiness:

○ Manage platform-specific release requirements including:

■ Windows EV Code Signing

■ Apple Notarization

■ Entitlements and security provisioning

4. Documentation & Knowledge Transfer

● Technical Documentation:

○ Produce detailed documentation covering:

■ IPC protocols

■ System architecture changes

■ State machines and threading models introduced during the

engagement

● Engineering Handover: Provide clear pull request documentation and structured

knowledge transfer sessions to ensure permanent engineering staff can maintain and

extend delivered components.

5. Ideal Experience

● Extensive experience with system-level networking development on Windows and

macOS

● Strong proficiency in Swift, C++, C#, and Go

● Deep familiarity with macOS NetworkExtension framework and Windows Filtering

Platform

● Experience designing and implementing secure interprocess communication

mechanisms

● Strong debugging and performance tuning skills in system-level networking

environments

● Experience working within production-grade security or networking software

● Ability to deliver high-quality code in a fast moving, project-based environment