Senior NTN & Network Test Engineer — Automation & Roaming

Skylo; Espoo; On-site; EUR 82,000 - 128,000; Full time

Benefits offered by this job

Stock option program

Medical, dental, vision, retirement

Wellness/education reimbursement

Generous time off

Job summary

Skylo is hiring a Senior IREG & Network Test Engineer to own the onboarding gate for roaming tests—moving from manual to automated, scalable validation across NTN networks. You will design test strategies, build automation, and collaborate with Signaling, Routing, Billing, NOC, and external partners.

This EU-based role emphasizes remote collaboration across time zones, with London as a hub and Europe-wide remote options for the right candidate.

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).
• Advanced protocol troubleshooting with Wireshark traces for multi-party failures.
• Proven experience designing automated telecom testing frameworks using Python and CI/CD.
• Fluent handling of IR.21/RAEX data profiles, PLMN structures, IMSI records, and TADIG codes.

Responsibilities

• Define the comprehensive IREG test strategy, pass/fail metrics, network tracing protocols, and official sign-off processes for each partner MNO.
• Run end-to-end roaming testing across registration, attach sequences, S6a/S6d authentication, SGd SMS-over-NAS, and IP/NIDD data paths.
• Develop automation harnesses and a lab capable of core GSMA and Skylo routing scenarios.
• Analyze traces and logs to isolate configuration issues across Skylo, IPX, and MNO domains.
• Manage defects through root cause analysis, remediation, and retesting; publish test coverage and dashboards.

Skills

Roaming validation

IREG testing

Python automation

CI/CD

Diameter/SS7 knowledge

Wireshark tracing

Automation framework design

IR.21/RAEX data profiles

Tools

Jira

Confluence

Job description

Skylo is hiring a Senior IREG & Network Test Engineer to own the onboarding gate for roaming tests—moving from manual to automated, scalable validation across NTN networks. You will design test strategies, build automation, and collaborate with Signaling, Routing, Billing, NOC, and external partners.

This EU-based role emphasizes remote collaboration across time zones, with London as a hub and Europe-wide remote options for the right candidate.