Principal 4G/5G Core Engineer

Iridium is an award-winning and innovative satellite communications company with bragging rights to the only network that offers voice and data connectivity anywhere in the world. For over 20 years, Iridium's unique network and services have supported critical communications needs for individuals, businesses, and the evolving Internet of Things.

At Iridium, we understand the importance of staying connected and the limitations of traditional communications networks. People across the globe, including first responders, humanitarians, global militaries, scientific researchers, and lone workers, as well as ships, aircraft and remote operations all rely on Iridium to stay connected. We take our responsibility for providing these essential communications very seriously and pride ourselves on offering a reliable lifeline when needed. Likewise, Iridium is committed to providing an exciting and innovative workplace, where employees are challenged to think outside the box and collaborate on new, bold ideas and solutions. Our talented teams are passionate about their work and the impact our company makes around the world. Iridium fosters an empowering and inclusive culture that allows employees to genuinely be their best selves. We are looking for others who want to join this truly unique company that celebrates our employees and provides the opportunity to truly make a difference in the world.

We are seeking an experienced Principal Core Engineer with deep expertise in 4G/5G Core networks to support both the deployment and long-term operation of cloud-based Core infrastructure at Iridium. In this role, you will lead and contribute to greenfield deployments of the Mavenir 4G/5G Core, while helping shape and mature Core operations over time. You will serve as a technical leader for complex network incidents, providing escalation support and ensuring stability, performance, and rapid service restoration across IMS, EPC, and 5GC domains. This position requires hands-on troubleshooting of critical network events, including deep protocol-level analysis and root cause resolution across multi-vendor environments. You will also play a key role in supporting cloud-based Core deployments and driving continuous operational improvement. Partnering across engineering and operations teams, you will help define best practices and strengthen overall Core reliability. Success in this role requires strong technical depth, proactive ownership, and the ability to lead incident response in a 24x7 environment.

Assist with the completion of greenfield deployment of multiple Mavenir Cores to the cloud
• Lead integration efforts and maintain connections with MNO Partners and Syniverse
• Provide escalation support for Mavenir 4G EPC and 5G Core network functions (AMF, SMF, UPF, PCF, NRF, IMS, SBC)
• Define, then monitor, and later evolve our ability to maintain Core network health
• Provide advanced troubleshooting across:
  • SIP, Diameter, GTP, HTTP/2, PFCP signaling
    
  • VoLTE/VoNR call flows
    
  • Data session establishment failures
    
• Lead Major Incident Management (MIM) calls for high-severity core outages
  
• Conduct deep Root Cause Analysis (RCA) using logs, traces, KPIs, and probe captures
  
• Correlate alarms and performance metrics to prevent false positives and reduce MTTR
  
• Perform cloud-native core deployments in Kubernetes and AWS-based environments
• Lead collaboration activities with RAN, Transport, and Cloud teams to resolve cross-domain issues
• Validate software upgrades, patches, and configuration changes in production
• Create and maintain SOPs, runbooks, and troubleshooting documentation
• Mentor junior engineers and provide technical training on Core network troubleshooting
• Ensure SLA/KPI compliance for availability, call success rates, and session setup times
• Participate in 24x7 on-call rotation and major incident bridge support

• Bachelor's degree in Telecommunications, Computer Science, Engineering, or related field; post-graduate degree preferred
• 10+ years of experience in telecom Core network operations
• Extensive, practical experience with a 4G/5G Core
• Deep understanding of:
  • 4G/5G Core architecture (EPC & 5GC SBA architecture)
  • IMS core and VoLTE/VoNR call flows
  • Diameter, SIP, GTPv2, PFCP, HTTP/2
• AWS certification (i.e., AWS Certified Cloud Practitioner, AWS Certified Advanced Networking, AWS Certified AI Practitioner, etc).
• Experience working in a cloud-native/Kubernetes environment
• Experience with containerized network functions (CNFs)
• Strong Linux command-line troubleshooting skills
• Experience analyzing packet captures using Wireshark or similar tools
• Familiarity with Kafka feeds and performance monitoring integrations
• Ability to perform structured RCA and document findings clearly
• Strong communication skills, with the ability to lead technical bridges and confidently present products, deliverables, analyses, and/or issues

• Knowledge of 3GPP practices and requirements
• Kubernetes certification (CKA/CKAD)
• Experience operating 4G Core networks (Mavenir is a plus)
• Experience operating 4G Ground RAN networks (Gatehouse is a plus)
• Good understanding or working knowledge of monitoring IOT device links
• Basic understanding or working knowledge of Non-Terrestrial Network (NTN) technologies
• Basic understanding or working knowledge of satellite-to-cell integration and 4/5G NTN architecture
• Hands-on experience with Grafana dashboard development and alarm correlation
• Experience with Viavi or probe-based call tracing
• Understanding of CI/CD pipelines for telecom cloud deployments
• Technical industry certification in Network+ or Linux (RedHat, CentOS, etc.)
• Experience with Core Cloud operations and best practices is highly desirable

• Travel up to 10%, as needed to support program-related activities

This position primarily works in an office setting and is largely sedentary with the majority of the position working with a computer. The role typically requires the use of basic office equipment such as a phone, video, computer, keyboard, mouse, and printer.

We believe in-person connection drives innovation, strengthens mentorship, and builds culture, while flexibility enables employees to do their best work. This is a fully onsite position requiring in-office attendance 5 days a week, to support collaboration, relationship-building, and professional growth.

Additional Information

This job description outlines the general nature and level of work for this role and is not a comprehensive list of duties, responsibilities, or qualifications. Employees may be assigned additional responsibilities as needed.

Iridium is an Equal Opportunity Employer, including individuals with disabilities and protected veterans.