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.

Experience
6-10 yrs