Senior Core Network Engineer (HLR/HSS & SDM)

This position is posted by Jobgether on behalf of a partner company. We are currently looking for a Senior Core Network Engineer (HLR/HSS & SDM) in Spain.

In this role, you will play a key part in designing and optimizing the core network infrastructure that enables seamless global mobile connectivity for millions of users. You will work on advanced HLR/HSS and subscriber data management systems, helping to ensure high-performance roaming experiences and scalable MVNO operations across international markets. This position offers the opportunity to tackle complex technical challenges in a highly collaborative and fully remote engineering environment. You will contribute to critical network innovations, improve roaming efficiency, and support large-scale telecom infrastructure projects with global impact. The role is ideal for a technically driven professional who enjoys working with cutting-edge mobile core technologies, solving signaling and roaming challenges, and driving operational excellence. You will collaborate with roaming partners, system integrators, and cross-functional engineering teams to shape the future of international connectivity solutions.

• Design, configure, and maintain HLR/HSS subscriber templates, including roaming profiles, APN/PDN contexts, and Camel/Diameter triggers.
• Optimize roaming efficiency through advanced Steering of Roaming (SoR) implementations and sponsor roaming integrations.
• Lead the deployment and management of Full MVNO profiles, including QoS configurations, addressing schemes, and independent network operations.
• Collaborate with roaming partners and external system integrators to refine network configurations and ensure alignment with operational objectives.
• Act as the primary technical contact for HLR/HSS-related projects, change requests, audits, and roadmap initiatives.
• Define, monitor, and improve critical KPIs related to signaling performance, location update success rates, and Diameter transaction throughput.
• Troubleshoot complex signaling and roaming issues using diagnostic and monitoring tools such as Wireshark and telecom testing platforms.
• Contribute to the evolution of subscriber data management strategies, network scalability, and operational automation initiatives.
• Support process optimization and ensure reliable, secure, and high-performing core network operations at global scale.

Requirements:

• Extensive experience in telecom core network engineering with strong expertise in HLR, HSS, SDM, or related subscriber management technologies.
• Deep understanding of MAP (SS7) and Diameter protocols, including S6a/S13 interfaces.
• Experience working within MVNO, MVNE, or multi-tenant mobile network environments.
• Strong knowledge of roaming technologies, Steering of Roaming (SoR), and sponsor IMSI management.
• Familiarity with GSMA IREG standards and understanding of TADIG processes and roaming settlement impacts.
• Proven troubleshooting capabilities for complex signaling and roaming issues using tools such as Wireshark, Mobileum, Roamware, or SIGOS.
• Experience collaborating with external roaming partners, vendors, and system integrators in complex technical projects.
• Knowledge of VoLTE roaming, SMSoIP, or 5G UDM/AUSF technologies is considered a strong advantage.
• Familiarity with cloud-native network functions (CNF), containerized deployments, or telecom virtualization environments is a plus.
• Scripting and automation skills using Python, Bash, or similar technologies are highly desirable.
• Excellent analytical thinking, communication, and problem-solving skills with the ability to work effectively in distributed teams.

Benefits:

• Competitive salary package aligned with experience and technical expertise.
• Fully remote work environment with flexibility and autonomy.
• Generous paid time off and work-life balance support.
• Wellness and professional development allowances to support personal growth and continuous learning.
• Opportunity to work on globally scaled telecom infrastructure and cutting-edge mobile connectivity technologies.
• Collaborative international environment with exposure to innovative engineering projects.
• Participation in company retreats, team-building initiatives, and global networking opportunities.
• Inclusive and diverse workplace culture focused on collaboration, innovation, and professional development.
• Potential healthcare coverage and additional employee benefits depending on employment terms and location.