Senior Core Network Engineer (HLR/HSS & SDM)

Ready to make travel easier for millions? Airalo is the world’s first and largest eSIM store, helping travellers stay connected seamlessly in over 200 countries and regions. We trust our teams to take ownership, put customers first, and do work that has a real impact every day. What’s in it for you? Airalo offers team members a range of perks, including remote work, generous PTO, wellness and learning allowances, and, of course, our annual Airalo Away retreat. Learn more about our benefits here; www.notion.so/airalo-public/Benefits-25396a97ffca81fb9bc1f0be479f1be3 Hi, I’m Peter, VP of Networks at Airalo! Our team ensures customers have instant, smooth connectivity from the moment they purchase their plan to the moment they arrive at their destination. We go beyond standard mobile service, building innovative solutions that enhance the traveller experience. We’re looking for curious engineers who want to design the future of global networks. Think outside the box, reverse-engineer solutions from ambitious product ideas, and help pave the way for Airalo’s leadership as a global connectivity partner. Airalo’s fully remote Networks team is growing. You’ll work on the systems and infrastructure that keep over 20 million travellers connected reliably and securely at global scale. Solve complex technical challenges, optimize processes, and experiment with better ways to keep the world connected. As our Senior HLR/HSS Specialist, you are the guardian of our subscriber data and the architect of our roaming efficiency. You won't just manage databases; you will own the life-cycle of HSS/HLR templates that allow our MVNO to scale globally. Your expertise in Profile & Template Engineering is critical to our success in maximising COGS and margin through sophisticated Steering of Roaming (SoR) and Sponsor Roaming integrations. Your main responsibilities will be: Design and maintain HLR/HSS subscriber templates, ensuring precise configuration of roaming profiles, APN/PDN contexts, and Camel/Diameter triggers. Collaborate with roaming partners to implement and refine SoR logic within the HLR/HSS, ensuring subscribers attach to preferred networks based on cost and quality. Lead the technical deployment of Full MVNO profiles, managing specific QoS profiles and addressing (GTs, APNs) required for independent network operations. Act as the primary technical point of contact for our System Integrators, auditing HLR/HSS configurations, reviewing change requests, and ensuring alignment with the 2026 roadmap. Define and monitor critical HLR/HSS KPIs, including Location Update (LU) success rates and Diameter Transaction per Second (TPS) limits. What you’ll need: Deep technical mastery of MAP (SS7) and Diameter (S6a/S13) protocols; additional experience with VoLTE Roaming (S8HR) or SMSoIP rollout is a significant advantage. Subscriber Mapping: Extensive experience with HLR, HSS, and UDM (User Data Management) in a multi-tenant or MVNO/E environment. Practical experience with Multi-IMSI applets and the logic required to manage roaming through Sponsor IMSIs. A solid understanding of GSMA IREG (IR series); familiarity with TADIG (TD series) and how HSS/HLR templates impact billing/settlement is preferred. A "detective" mindset for troubleshooting complex signalling failures using tools like Wireshark or roaming-specific platforms (e.g., Mobileum, Roamware, or SIGOS). Proven ability to manage technical projects with external System Integrators and roaming partners under tight deadlines. Bonus Points Experience with 5G Unified Data Management (UDM) and Authentication Server Functions (AUSF). Knowledge of Cloud Native Network Functions (CNF) and containerised core deployments. Scripting skills (Python/Bash) for automating provisioning audits or log parsing. If you are interested in this position, please apply via the link. By applying, you acknowledge and agree that, in case of successful application, Airalo may request to run background checks as a condition for entering into an agreement with you. Rest assured that these checks will only occur upon your prior consent and at the end of the selection process, and will be strictly limited to what is allowed under the laws that are applicable to you. All data that you share or that we collect in connection with such checks will be processed in accordance with our Privacy Policy, available here: www.airalo.com/more-info/privacy-policy?srsltid=AfmBOooBT0rXAj1FaNelZ3VfN0wvhwzvAoxdtHnOKSVETpiSjiXVuycy We sincerely thank all applicants in advance for submitting their interest in this opportunity. Airalo is an equal-opportunity employer and values diversity, equity & inclusion. We do not discriminate on the basis of race, religion, national origin, gender, sexual orientation, age, marital status, veteran status, or disability status. We are committed to providing reasonable accommodations upon request for individuals with disabilities throughout our job interview process.