HLR/HSS/UDM Architect

Responsibilities

• Manage and operate HLR, HSS, UDR, and UDM nodes across 2G, 3G, 4G, and 5G core domains
• Design and maintain subscriber provisioning workflows including IMSI/MSISDN management and roaming configurations
• Implement and verify MAP, Diameter, and HTTP/2-based interfaces
• Build and use dashboards to monitor subscriber node KPIs and identify abnormal conditions
• Own incident management for the subscriber data domain and coordinate with external vendors
• Perform maintenance, security audits, patching, and emergency response for subscriber platforms
• Conduct protocol trace analysis using Wireshark or tcpdump on Diameter, MAP, and HTTP/2 signaling
• Lead project activities including E2E introduction of new nodes and capacity expansions
• Support MVNO onboarding by configuring subscriber data repositories and roaming agreements
• Participate in a 7x24 on-call rotation and maintenance window monitoring

Requirements

• 10+ years of experience in core telecommunications network engineering
• Minimum 5 years hands-on experience with HLR, HSS, UDR, or UDM platforms
• Deep knowledge of HLR platforms and MAP/TCAP/SCCP signaling stacks
• Hands-on experience with HSS platforms and Diameter-based interfaces (S6a, S6d, Cx, Sh, Zh)
• Practical experience with 5G UDM and UDR, including cloud-native/Kubernetes deployments and HTTP/2 SBI interfaces
• Strong knowledge of SS7 stack (MAP, TCAP, SCCP, MTP)
• Expertise in Diameter protocol, including peer configuration and routing
• Working knowledge of 2G, 3G, 4G, and 5G SA core architectures
• Proficiency with Linux/Unix-based systems and shell navigation
• Experience with Wireshark and tcpdump for signaling analysis
• BSc degree in Telecommunications, Computer Science, or equivalent

Preferred Qualifications

• 2+ years of scripting experience in Python or Bash for automation
• Experience with AUSF, UDSF, or PCF in 5G SA environments
• Familiarity with cloud-native platforms like OpenShift or Kubernetes
• Exposure to OSS/BSS integration and provisioning APIs
• Knowledge of eSIM (GSMA SGP.02 / SGP.22)
• Experience with MVNO/MVNE operating models

About the Company

OXIO is an evolving MVNO platform working toward 5G standalone architecture, focusing on reliability and scalability for network partners.