Network Software Engineer

Description Leidos has a new and exciting opportunity for a Network Software Engineer in our National Security Sector's (NSS) Cyber & Analytics Business Area (CABA) . Our talented team is at the forefront in Security Engineering, Computer Network Operations (CNO), Mission Software, Analytical Methods and Modeling, Signals Intelligence (SIGINT), and Cryptographic Key Management. At Leidos , we offer competitive benefits, including Paid Time Off, 11 paid Holidays, a 401K with a 6% company match and immediate vesting, Flexible Schedules, Discounted Stock Purchase Plans, Technical Upskilling, Education and Training Support, Parental Paid Leave, and much more. Join us and make a difference in National Security! The Network Software Engineer will support DARPA's QuANET program. The role focuses on building and testing software that integrates network emulation, routing, telemetry, and cyberresponse logic. The developer will work hands‑on with Python and C++, create reproducible test environments, debug Linux and container networking issues, and collaborate with senior engineers across hardware, cyber, and networking teams. Strong systems and distributed networking skills are essential; quantum‑domain experience is not required. Candidates with deep implementation ability and broad networking expertise are preferred. Primary Responsibilities Design, implement, and test network systems software in Python and C++. Build and debug Linux‑based network topologies using namespaces, veth pairs, bridges, iproute2, iptables/nftables, and traffic‑control tooling. Develop and maintain containerized network emulation environments using Docker and related container networking patterns. Integrate inter‑process messaging such as ZeroMQ, gRPC, protobuf, or similar mechanisms. Support reproducible CI/CD and regression testing for network and systems code. Use network simulation or emulation tools such as Containerlab, Kathara, Mininet, ns-3, GNS3, or equivalents. Troubleshoot distributed behavior such as convergence, message ordering, failure detection, and eventual consistency. Write clear design notes, implementation plans, and technical status updates for mixed technical and non‑technical audiences. Participate in code review and collaborate with cross‑functional research teams. Basic Qualifications Bachelor's degree in computer science, computer engineering, electrical engineering, networking, or a related technical field and 4‑8 years of relevant experience, or a master's degree with 2‑6 years of relevant experience; additional relevant experience may be considered in lieu of a degree. Hands‑on programming experience in Python and C++, with strength in at least one and working competence in both. Experience building, operating, or debugging a distributed system at non‑trivial scale, such as consensus systems, message brokers, service meshes, distributed databases, routing systems, or comparable systems. Practical Linux networking experience, including namespaces, veth pairs, bridges, iproute2, iptables/nftables, and tc. Docker or container networking experience beyond basic container usage, including bridge, macvlan, host networking, CNI, or multi‑container interconnect patterns. Familiarity with inter‑process messaging frameworks such as ZeroMQ, gRPC, protobuf, or similar. Experience with C++ build and debug tooling such as CMake, gdb, valgrind, perf, or equivalents. Experience with standard Python development, testing, and packaging workflows. Experience contributing to CI/CD or reproducible test environments for systems, networking, or software projects. Git fluency and experience participating in code review. Must be a U.S. citizenship with ability to obtain and maintain a U.S. government security clearance. Preferred Qualifications Working knowledge of routing protocols such as BGP, OSPF, IS‑IS, or similar, including ability to read and interpret RFCs. Experience with FRR, Bird, Quagga, GoBGP, or other open‑source routing stacks. Prior contribution to open‑source routing daemon or network‑stack projects. Experience with network operating systems such as SONiC, Cumulus, VyOS, or comparable systems. Experience with streaming telemetry or observability stacks such as gNMI, OpenConfig, Prometheus, or Grafana. Experience with Containerlab, Kathara, Mininet, ns-3, GNS3, or comparable network emulation/simulation tooling in production‑grade use. Prior experience on government‑funded R&D programs such as DARPA, IARPA, ONR, AFRL, ARL, DOE, or NSF. Experience with tactical, contested, or resilient networking. TS/SCI Security Clearance. Commitment to Non-Discrimination All qualified applicants will receive consideration for employment without regard to sex, race, ethnicity, age, national origin, citizenship, religion, physical or mental disability, medical condition, genetic information, pregnancy, family structure, marital status, ancestry, domestic partner status, sexual orientation, gender identity or expression, veteran or military status, or any other basis prohibited by law. Leidos will also consider for employment qualified applicants with criminal histories consistent with relevant laws. Original Posting: June 24, 2026 Pay Range: $87,100.00 - $157,450.00 #J-18808-Ljbffr