Staff Software Engineer – Low-Level Networking Agent

• Participate in design and implementation strategies to enhance and improve ZeroTier’s networking agent
• Develop and maintain communication primitives using protocols such as TCP and UDP, as well as custom transport layers
• Implement secure tunneling, NAT traversal techniques, and robust reconnection/keepalive mechanisms
• Work with low level, OS-specific operations (sockets, netlink, firewall rules, etc.) to optimize data paths
• Profile and optimize network performance (latency, throughput, connection reliability)
• Build cross-platform abstractions enabling the agent to run in varied environments
• Write clean, maintainable, well-tested code and contribute to architecture documentation
• Collaborate with cross-functional teams on system design, threat modeling, and deployment strategies

• Senior Level experience in network engineering or systems programming
• Strong proficiency in C, C++ or Rust for low-level development
• Deep understanding of: Networking and protocols: OSI Model, IPv4/IPv6, IP routing, Ethernet
• Internet routing, including IPAM, firewalls, NAT, multipath
• NAT traversal techniques (STUN/TURN/ICE, hole punching)
• Encryption standards and secure session establishment
• Experience with Linux and/or Windows networking internals and socket programming
• Familiarity with overlay networks, VPN tunneling, mesh networking, or SD-WAN
• Solid debugging and performance profiling skills using tools like tcpdump, Wireshark, perf, strace, etc.
• Ability to write technical documentation and communicate effectively with team members
• Experience in a startup or fast-paced environment is a strong plus

Experience in a startup or fast-paced environment is a strong plus