Senior IREG & Network Test Engineer

Skylo Technologies; Finland; On-site; EUR 90,000 - 120,000; Full time

Job summary

Skylo Technologies in Espoo, Finland, seeks a Senior IREG & Network Test Engineer to own the onboarding gate from initial attach to roaming sign-off. You will replace manual partner-dependent testing with scalable automation and a regression pipeline.

Join a high-velocity global team, work onsite three days a week, and help build the world’s first commercial direct-to-device satellite network with Skylo’s NTN vRAN platform.

Qualifications

• 5+ years of hands-on experience in roaming validation, mobile core operations, interconnect routing, IREG testing, or telecommunications network testing.
• Strong understanding of Diameter routing and SS7/MAP concepts (S6a/S6d, SGd, roaming authentication/registration flows).
• Advanced debugging with Wireshark traces across external parties.
• Experience designing automated telecom testing frameworks using Python and CI/CD.
• Proficient handling of IR.21/RAEX data profiles, PLMN structures, IMSI records, and TADIG codes.

Responsibilities

• Develop Test Strategy: Define comprehensive IREG test strategy, pass/fail metrics, network tracing protocols, and sign-off processes for each partner MNO.
• Execute Roaming Validation: Run end-to-end roaming testing across network registration, attach sequences, S6a/S6d authentication, SGd SMS-over-NAS, and IP/NIDD data paths.
• Optimize for NTN: Execute GSMA-defined roaming test suite while introducing NTN-specific validation cases.
• Build Automation Harnesses: Build and maintain an automation test harness and lab for GSMA and Skylo routing scenarios.
• Trace Analysis: Analyze Diameter/SS7 traces and logs to isolate configuration issues across Skylo, IPX, and MNO domains.
• Defect Management: Convert onboarding failures into regression tests; drive root-cause analysis and remediation.
• Portfolio Metrics: Publish test coverage, cycle-time, defect rates, and readiness dashboards for onboarding leadership.
• Cross-Functional Partnering: Coordinate with Signaling, Routing, Billing, NOC, Product, IPX vendors, and MNO test squads.

Job description

The world still has coverage blind spots. You could help eliminate them at Skylo.

Skylo has pioneered a standards-based approach to satellite connectivity. We connect smartphones and IoT devices directly to satellites. No special hardware, no entirely new networks. Just billions of existing devices, suddenly reachable anywhere on Earth. We're not building toward this future. We're already in it.

Our direct-to-device service is live on millions of activated devices across five continents, covering more than 72 million square kilometers, in partnership with leading satellite operators, mobile network operators, Tier-1 chipset makers, and OEMs worldwide. And we're just getting started.

At the heart of it all is Skylo's commercial NTN vRAN: a 3GPP standards-based, cloud-native platform that seamlessly bridges terrestrial and satellite networks. It's the infrastructure that makes true anywhere, anytime connectivity possible.

When you join Skylo, you'll work at the intersection of three markets reshaping how the world stays connected: mass-market consumer devices, automotive, and industrial IoT. Enabling people outdoors and critical workflows in the world's most remote places.

This is a rare chance to work on technology that matters, at a company that's already proving it works

This role is based in Espoo, Finland, one of Skylo's core engineering hubs and fastest-growing sites. You'll work onsite three days a week as part of a team that's scaling quickly. You will collaborate with a high-velocity, global team spanning multiple time zones.

ABOUT THE ROLE:

Every Mobile Network Operator (MNO) onboarding timeline ends at a critical technical test gate. We are hiring an automation-oriented Senior IREG & Network Test Engineer to own that gate-from initial attach and authentication through SGd, MAP, SMS, IP NIDD, and roaming sign-off. You will replace manual, partner-dependent execution with a repeatable test strategy, a scalable testing environment, and an automated regression pipeline.

RESPONSIBILITIES:

• Develop Test Strategy: Define the comprehensive IREG test strategy, pass/fail metrics, network tracing protocols, and official sign-off processes for each partner MNO.
• Execute Roaming Validation: Run end-to-end roaming testing across network registration, attach sequences, S6a/S6d authentication, SGd SMS-over-NAS, and IP/NIDD data paths.
• Optimize for NTN: Execute the standard GSMA-defined Roaming test suite while ideating and introducing custom validation test cases built specifically for NTN (Non-Terrestrial Networks).
• Build Automation Harnesses: Build and maintain an automation test harness and lab capable of running core GSMA and Skylo-specific routing scenarios consistently.
• Trace Analysis: Analyze Diameter/SS7 traces along with device and network logs to cleanly isolate configuration issues across Skylo, IPX, and MNO domains.
• Defect Management: Turn production and onboarding failures into repeatable regression test cases, managing defects through root cause analysis, remediation, and retesting.
• Portfolio Metrics: Publish clear test coverage, validation cycle-time, defect rates, and market-readiness dashboards for the onboarding leadership team.
• Cross-Functional Partnering: Coordinate closely with internal Signaling, Routing, Billing, NOC, and Product teams, as well as external IPX vendors and MNO test squads.

REQUIRED QUALIFICATIONS:

• 5+ years of hands-on experience in roaming validation, mobile core operations, interconnect routing, IREG testing, or telecommunications network testing.
• Strong understanding of Diameter routing and relevant SS7/MAP concepts (including S6a/S6d, SGd, and roaming authentication/registration flows).
• Advanced protocol troubleshooting skills with experience reading Wireshark traces to diagnose failures involving multiple external parties.
• Proven experience designing automated telecommunications testing frameworks using Python (or comparable languages) integrated with modern CI/CD practices.
• Complete fluency handling IR.21/RAEX data profiles, PLMN structures, IMSI records, and TADIG codes.

PREFERRED QUALIFICATIONS:

• Practical experience with NB-IoT, NTN satellite architectures, NIDD data paths, or cellular device-lab environments.
• Familiarity with IMSI Tracing tools, carrier-grade Diameter/SS7 diagnostic platforms, Jira, and Confluence.
• Direct experience integrating network signaling validation with TAP/BCE billing verification.

WHAT WE OFFER

This is a once-in-a-lifetime opportunity to help build and run the world's first commercial, live direct-to-device satellite network. You'll work alongside a world-class team spanning software, hardware, chipsets, telecom, satellite, and network virtualization, some of the most sought-after expertise in the industry. And you'll do it inside a culture that is open, transparent, and inclusive, shaped by the best of Silicon Valley, Nordic, and South Asian ways of working.

With employees working across three continents, Skylo is proud