Core Network Lead (Mobile Core)

Location: Remote, open to candidates across supported locations in Europe

Salary: UK £89,600–£128,800; Ireland €76,800–€110,400; Western & Southern Europe €50,800–€116,117; Central, Eastern Europe & Caucasus €53,851–€88,291. Local market rates determine the specific range.

Company

hirify.global operates a global eSIM store that provides mobile data connectivity to travelers in more than 200 countries and regions.

What you will do

• Lead and mentor a Build Team of approximately five engineers and QA specialists across concurrent rollout streams.
• Architect, integrate, test, and commission Full MVNO core capabilities and host MNO integrations.
• Design and configure subscriber databases, packet core, signalling routing, messaging platforms, and voice services.
• Lead troubleshooting across Diameter, SS7, and SIP, including data, VoLTE, legacy circuit-switched voice, SMS, and international interconnects.
• Implement mobile number portability routing and ensure lawful interception and emergency-service routing compliance.
• Drive integration testing, stress testing, acceptance testing, operational readiness reviews, and documented handovers to the 24/7 Run team.

Requirements

• At least 5 years of hands-on experience with mobile core networks and Full MVNO integrations.
• At least 2 years leading engineering and/or QA specialists in an agile or delivery-focused environment.
• Strong knowledge of packet core and voice core systems, including HSS/HLR, policy and charging, VoLTE, and circuit-switched voice.
• Expertise in Diameter, SS7, SIP, messaging architecture, and SMS routing with operator interworking.
• Experience delivering mobile number portability and lawful interception solutions.
• English is the main working language and is required for meetings and asynchronous communication.

Nice to have

• Experience with CI/CD, infrastructure as code, Terraform, Ansible, Docker, Kubernetes, or automated signalling test frameworks.
• Experience with MVNO vendors such as Nokia, Ericsson, Mavenir, Oracle Communications, Cisco, Summa Networks, NetNumber, or XIUS.
• Experience with cloud-native or virtualised network functions on AWS, Azure, GCP, or private cloud.
• Degree in telecommunications engineering, computer science, electrical engineering, or a related field.

Culture & Benefits

• Fully remote work with a team distributed across more than 60 countries.
• Trust, ownership, autonomy, and minimal bureaucracy.
• Participation in a paid on-call rotation with standby fees and overtime pay.
• No on-call duties during the first six months.
• Guaranteed rest periods and flexible hours after night incidents, with weekday and weekend rotations split to reduce fatigue.