Staff Software Engineer

Responsibilities:

• Design and implement transparent network traffic interception on macOS using Apple's Network Extension framework.
• Build selective traffic redirection for AI applications while minimising impact on non-managed network traffic.
• Design and implement communication between the Network Extension and the endpoint service responsible for proxy coordination, authentication, and policy management.
• Architect traffic steering mechanisms that securely redirect eligible traffic to the cloud inspection platform.
• Design resilient handling of application launches, network changes, sleep/wake cycles, interface changes, captive portals, and roaming scenarios.
• Ensure seamless coexistence with enterprise VPN clients, SASE agents, endpoint security products, and other Network Extension-based software.
• Investigate and resolve interoperability issues involving routing, DNS, proxy configuration, packet processing, and competing network extensions.
• Design mechanisms for selectively intercepting traffic before enterprise proxy or SASE products when appropriate while maintaining compatibility with enterprise networking policies.
• Optimise CPU utilisation, memory footprint, connection latency, and startup performance for enterprise laptop deployments.
• Build comprehensive diagnostics, health monitoring, and troubleshooting capabilities for complex customer environments.
• Collaborate closely with endpoint service, cloud platform, security, Windows, and backend engineering teams to define clean APIs and system contracts.
• Participate in customer escalations involving networking interoperability and complex enterprise deployments.
• Mentor engineers and help define the long-term macOS networking architecture.

Requirements:

• 6+ years (Senior) / 9+ years (Staff) of professional software engineering experience.
• Extensive hands-on experience building production software using Apple's Network Extension framework.
• Proven experience shipping enterprise networking products on macOS.
• Deep understanding of Network Extension providers, transparent proxy architectures, packet flow, DNS handling, and network routing.
• Strong understanding of the macOS networking stack, including interface management, routing, DNS resolution, TLS, and proxy behaviour.
• Experience diagnosing complex interoperability issues involving VPN clients, proxy software, endpoint security agents, and other network extensions.
• Strong systems programming skills in Swift, Objective-C, or C/C++, with the ability to work across language boundaries where appropriate.
• Experience building highly reliable background services and privileged system components.
• Strong debugging skills using macOS networking diagnostics, packet captures, system logs, and performance analysis tools.
• Excellent communication skills and the ability to collaborate across multiple engineering teams.
• Strongly Preferred Experience building endpoint security products such as: Endpoint DLP, EDR/XDR o Secure Web Gateway (SWG), SASE endpoint client o VPN client, Zero Trust Network Access (ZTNA) client, Endpoint Firewall.
• Deep experience with: Transparent Proxy Provider, Packet Tunnel Provider, App Proxy Provider, Network Filter Provider, System Extensions, Endpoint Security Framework (ESF).
• Experience integrating with enterprise identity and device management platforms.
• Experience designing networking software that coexists with products from vendors such as Zscaler, Palo Alto Networks, Netskope, Cisco, Microsoft, Cloudflare, or similar enterprise networking platforms.
• Familiarity with enterprise certificate management, proxy authentication, TLS interception, and trust distribution.
• Experience supporting large enterprise deployments managed through Jamf, Intune, Kandji, or similar MDM platforms.

Skills

C++, Network Extension, Objective-C, Swift, System Extensions, macOS