Senior IREG & Network Test Engineer

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 remote UK-based position places you at the core of Skylo's European partner ecosystem. You will collaborate with a global team spanning multiple time zones. While London is our hub, we are open to remote arrangements for the right candidate located elsewhere in Europe.

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's 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 to be an equal opportunity employer dedicated to building an inclusive and diverse workforce. Our worldwide and inclusive culture encourages a flexible approach to work, and we also offer an attractive range benefits such as:

• Competitive compensation packages including a stock option based equity program
• Comprehensive benefits including medical, dental, vision, retirement plan
• Monthly allowances for wellness and education reimbursement
• A generous time off policy, holidays, and the opportunity to temporarily work abroad

EEO STATEMENT

Skylo is an equal-opportunity employer and we celebrate diversity. We do not discriminate based on race, religion, color, ancestry, national origin, caste, sex, sexual orientation, parent or caregiver status, political affiliation, gender, gender identity or expression, age, disability, medical condition, pregnancy, genetic makeup, marital status, or military service consistent with applicable federal, state, and local laws.

We are also committed to providing reasonable accommodations for qualified individuals with disabilities and disabled veterans in our job application procedures. Please let us know if you need assistance or accommodation due to a disability.