SIM Management, 5G Core Engineer

Subscriber platform reliability. Manage and operate UDR and UDM nodes in the 5G Core domain. Maintain high availability and subscriber profile integrity, and verify configuration and integration across nodes, networks, and systems.

Provisioning and onboarding. Design and maintain subscriber provisioning workflows covering IMSI/MSISDN management, service profiles, and roaming configurations. Configure subscriber repositories, IMSI ranges, and roaming agreements to support onboarding.

Interface integration. Implement and verify HTTP/2-based interfaces, including N8 and Nudm, connecting subscriber data nodes to AMF and other core elements. Validate subscriber data exchanges and resolve integration defects.

Operational visibility. Use and build dashboards to monitor subscriber node KPIs. Surface abnormal conditions promptly and identify patterns before they become outages.

Incident resolution. Own incident management for the subscriber data domain. Follow internal escalation and external vendor communication procedures, coordinate recovery, and ensure SLAs are met.

Platform maintenance and security. Perform maintenance, security audits, patching, and emergency response for UDM/UDR platforms. Verify service health after changes.

Lasting corrective action. Handle faults at node, service, and infrastructure levels. Analyze HTTP/2 signaling with Wireshark and tcpdump, identify root causes, and verify corrective actions.

Platform evolution. Lead and contribute to end-to-end introduction of subscriber management nodes, capacity expansions, software upgrades, and feature activations. Track dependencies and validate functionality and capacity before closing the work.

Cross-domain delivery. Work with partner teams to resolve subscriber authentication and registration issues. Make ownership and next steps clear, escalate blockers early, and follow through on resolution.

Deep operational knowledge of HSS/HLR or UDR/UDM platforms, with hands-on configuration and troubleshooting experience.

Practical experience with 5G UDM and UDR, including cloud-native, containerized or Kubernetes-based network functions and HTTP/2 service-based interfaces: N8, Nudm_SubscriberDataManagement, and Nudr_DataRepository.

Solid understanding of 5GS subscription profile structures, IMSI/MSISDN range management, number portability (NP/MNP) integration, and SIM/eSIM provisioning workflows.

Working knowledge of 5G SA architectures, including AMF, SMF, UDM, UDR, AUSF, and UDSF, and their subscriber data flows.

Familiarity with 3GPP TS 29.503 and TS 29.504 for UDM/UDR service-based interfaces, and TS 23.502 for 5G procedures.

Comfort with Linux/Unix shells, log interpretation, process management, and basic system administration on telecom network function hosts.

Hands-on experience with Wireshark, tcpdump, and vendor-specific trace tools for analysis of MAP, Diameter, and HTTP/2 subscriber signaling.

Experience with active/standby configurations, geo-redundancy, and database replication and synchronization for highly available subscriber databases.

Familiarity with Kubernetes-based telecom platforms and Helm-based network function lifecycle management.

Experience with 3GPP NTN core adaptations in Releases 17 and 18, including satellite access node (SAN) architecture, timer and window parameter adaptation for high-latency links, or UPF placement in non-terrestrial topologies.

Background in MVNO core architecture, including roaming interfaces such as N32/SEPP and Diameter S6a/S9, multi-PLMN federation, MVNO interconnect, or eSIM/SM-DP+ integration.