Principal Solutions Architect, Core & Signalling

Skylo Technical Subject Matter Expert

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

About Skylo

Skylo is helping redefine how the world stays connected. At Skylo, our mission is to extend reliable connectivity to people, vehicles, and devices wherever they operate, even in the most remote and hard-to-reach places.

Skylo is a global connectivity company serving customers and partners worldwide. We enable satellite-based connectivity for everyday devices, helping smartphones, vehicles, and machines stay connected beyond traditional cellular coverage. Today, Skylo's services are live on millions of devices across five continents, supporting use cases across consumer devices, automotive, and industrial sectors.

This role is located in North America following a hybrid working arrangement, spending 1–3 days per week based on the role and team needs.

Summary Of How You Will Impact Skylo

Skylo is looking for a Principal-level Technical Subject Matter Expert (SME) to own the end-to-end technical integrity of our Core and Signaling architecture. This is not a project management role; it is a "boots-on-the-ground" technical leadership position. You will be the ultimate authority on 3GPP 4G/5G signaling, responsible for designing the complex call flows that bridge Satellite (NTN) and Terrestrial networks. You will lead the "deep-room" technical sessions with MNO architects and build the definitive technical repository for Skylo's core capabilities

What The Role Will Look Like - Core Responsibilities

1. Global Roaming Architecture & Core Integration

   • Act as the technical authority for global roaming and interconnect architecture across Skylo's NTN core and MNO partner networks

   • Architect roaming connectivity using key interfaces, including S8, S6a, T7.

   • Lead the integration of Skylo's NTN core with operator MME/SGW/PGW/5GC components.

   • Work closely with MNO core engineering teams to validate interoperability, performance, and operational readiness.

   • Design signalling procedures that are resilient to high-latency NTN environments, ensuring stable registration, SMS delivery, and session establishment

   • Support global MNO integrations through workshops, architecture sessions, and troubleshooting.

2. IPX Interconnect & Roaming Operations

   • Manage technical relationships with IPX providers, including peering architecture, routing, QoS, and redundancy.

   • Hands-on expertise with Diameter Routing Agents (DRA) and Diameter Edge Agents (DEA) for routing and security across interconnect domains.

   • Design and troubleshoot Diameter routing policies, realm-based routing, and failover mechanisms.

   • Strong operational understanding of DNS-based roaming discovery, including NAPTR/SRV resolution used in Diameter routing and IPX interconnect environments.

   • Diagnose and resolve complex signalling issues involving Diameter routing, IPX routing policies, and multi-hop interconnect paths.

   • Support troubleshooting of complex roaming issues across IPX, signalling, and core network domains.

   • Collaborate with commercial and operational teams to ensure scalable roaming connectivity across global partners.

3. Signalling Architecture & Call Flow Expertise

   • Design and validate end-to-end NB-IoT roaming procedures, including NTN-specific registration and session management flows.

   • Troubleshoot and optimise signalling procedures for:

     1. Registration and Attach

     2. Session Establishment

     3. Paging and Mobility

   • Architect and manage SMS-over-NAS (CP/RP) procedures, including synchronisation between Skylo MME and MNO SMSCs.

   • Perform detailed signalling analysis using packet traces and call flow debugging.

   • Deep protocol expertise across:

     1. Diameter

     2. SCTP

     3. GTP-C / GTP-U

     4. 3GPP signalling procedures

4. Technical Documentation & Standards

   • Develop and maintain the Skylo technical architecture repository.

   • Translate complex 3GPP and NTN architecture concepts into actionable guidance for internal engineering teams

   • Author and maintain key technical documentation including:

     1. Interface Control Documents (ICDs)

     2. High-Level Designs (HLDs)

     3. Call Flow Sequence Diagrams

   • Produce troubleshooting and operational documentation for edge cases unique to NTN environments.

   • Create and maintain GSMA IR.21 documentation, with strong familiarity with the GSMA Member Gateway.

   • Represent Skylo in GSMA working groups and technical forums where required

What We Look For

• 10+ Years of Telecom Rigour: Extensive experience in 4G/5G Core Network architecture

• Experienced in LTE EPC and/or 5G Core environments, with strong familiarity across control plane and user plane signalling, Diameter, GTP, and key 3GPP interfaces

• Hands-on experience with international roaming and IPX interconnects

• Experience working directly with MNO core teams and IPX providers

• Strong familiarity with GSMA roaming frameworks and documentation (IR.21, IR.88, etc.)

• Proven ability to design and debug complex telecom signalling flows

• Documentation Specialist: A passion for clarity. You take pride in creating diagrams and documents that are technically flawless and easy to navigate

What We Offer

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 plans

• Monthly allowances for wellness and education reimbursement

• A generous time off policy and holidays

• Once in a lifetime opportunity to be a part of developing and running world's first commercial, live direct-to-device satellite network and service

• Access to world-class team and talent across tech domains: software, hardware, chipsets, telecom, satellite and network virtualization

Additional Information