> Markdown version of [/jobs/ext/4509748-principal-software-engineer-5g-core-networks](https://www.wearedevelopers.com/jobs/ext/4509748-principal-software-engineer-5g-core-networks). Every page supports `.md` or `Accept: text/markdown`. Links point to the HTML versions so they work for humans too. Agent guide: [/agents.md](https://www.wearedevelopers.com/agents.md).

---

# Principal Software Engineer - 5G Core Networks

- **Company:** RTX
- **Location:** San Jose, CA, United States (Remote available)
- **Experience:** Expert
- **Salary:** $118,300.0 - $224,900.0
- **Contract:** Permanent contract
- **Skills:** Microsoft Access, 4G (Telecommunication), Application Programming Interfaces (APIs), Amazon Web Services, Linux, Distributed Systems, Python (Programming Language), Kernel-Based Virtual Machine, Network Functions Virtualization, Network Interface, Network Monitoring, Network Virtualization, OpenStack, Prometheus, Reverse Engineering, Session Management, Software Engineering, Software Systems, Grafana, Containerization, Kubernetes, Decoding, C++14, Docker, Vmware, Microservices
- **Published:** November 1, 2026
- **Apply:** https://www.adzuna.com/details/5890578395

## About the Role

The ability to obtain and maintain a U.S. government issued security clearance is required. U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance, * Typically requires a degree in Science, Technology, Engineering or Mathematics (STEM) and a minimum of 8 years of prior relevant experience

 * Aggregate of 5 years software development experience in one or more of the following areas:
 * Developing 3GPP network functions, network interfaces, and/or service-based interfaces, such as:
 * User Plane Function (UPF), Access and Mobility Management Function (AMF), and/or Session Management Function (SMF),
 * N4 and/or N11 network interfaces, and/or
 * Namf, Nsmf, and/or Nupf services.
 * Developing protocols such as NAS, PFCP, GTP-U, and/or HTTP/2.
 * Reverse engineering telecommunications protocols.
 * Troubleshooting distributed systems and control-plane signaling paths.
 * Using 5G core network control-plane probes.
 * Developing service-based microservices with REST-like APIs.
 * Demonstrated expertise developing Linux-based software systems utilizing modern C++, Python, or equivalent environments to architect, implement, and validate complex telecommunications processing solutions.
 * Ability to obtain and maintain a U.S. government issued Top Secret SCI (TS/SCI) security clearance with polygraph after start.
 * U.S. citizenship is required, as only U.S. citizens are eligible for a security clearance.

Qualifications We Prefer:

 * Existing U.S. government issued TS/SCI security clearance with polygraph or current SSBI.
 * Knowledge of AMF, SMF, UPF, UDM, PCF, AUSF, NRF behavior, interactions, and call flows.
 * Experience developing 5G core network control-plane probes for monitoring network traffic, extracting signaling and user-plane information, decoding 3GPP protocols, and/or traffic replay.
 * Experience with observability frameworks (OpenTelemetry, Prometheus, Grafana)
 * Familiarity with 4G EPC (MME, SGW, PGW, HSS).
 * Familiarity with network virtualization and/or containerization technologies (KVM, VMware, OpenStack, AWS, Kubernetes, Helm, Docker).
 * Experience developing with Go or Rust.

## Description

* Apply your 5G Core Network software development experience to advance our next generation mobile telecommunication processing solutions by:
 * Collaborating with technical leaders to further product visions and roadmaps and developing innovative software solutions,
 * Collaborating with customers to elicit requirements and CONOPS, and
 * Performing technical research, developing technical documentation, presentations, and/or leading concept demonstrations.
 * Travel up to 15% travel time to other AST sites and customer sites to support customers meetings and/or demonstrations, system deployments.