Senior Core Network Solution Architect

TL;DR

Senior Core Network Solution Architect: Designing high-level solutions for data, voice (VoLTE/VoNR), and messaging (SMSoIP) services, ensuring seamless integration between the Packet Core (EPC/5GC) and IMS domains. Focus on optimizing data session flows, leading technical discussions with IPX/GRX providers, and transitioning from 4G to 5G Standalone (SA).

Location: Remote (Europe)

Company

hirify.global is the world’s first and largest eSIM store, helping travellers stay connected seamlessly in over 200 countries and regions.

What you will do

• Own the HLD and LLD for Core Network services, ensuring seamless integration between the Packet Core (EPC/5GC) and IMS domains.
• Lead the technical rollout of VoLTE Roaming (S8HR) and SMSoIP strategies, ensuring high-quality voice and messaging services across diverse roaming partners.
• Design and optimise data session flows, including Local Breakout and Home Routed architectures to minimise latency for global users.
• Lead technical discussions with IPX/GRX providers and Equipment Vendors to secure the best architectural paths for our traffic.
• Act as the Subject Matter Expert for the transition from 4G to 5G Standalone (SA), focusing on the deployment of the Service-Based Architecture (SBA).

Requirements

• Extensive experience in Core Network architecture within a Tier 1 Carrier, MVNO, or major vendor environment.
• Deep understanding of the IMS (IP Multimedia Subsystem) architecture and how it interacts with the EPC/5GC for VoLTE and SMS services.
• Expert-level knowledge of SIP, Diameter, and GTP signalling.
• Strong grasp of IPX/GRX connectivity and the BGP/DNS logic (S-NAPTR) required for global network discovery.
• Ability to lead "Acceptance Testing" (ATP) and technical workshops with external stakeholders to ensure designs are implemented to spec.

Nice to have

• Experience with Cloud Native Network Functions (CNF) and deploying core elements in AWS/GCP/Azure environments.
• Knowledge of 5G Slicing and how it applies to specialised data services.
• Previous experience in an MVNE/MVNO environment during a high-growth phase.

Culture & Benefits

• Remote work environment.
• Generous PTO.
• Wellness and learning allowances.
• Annual hirify.global Away retreat.