Principal Solutions Architect – Core & Signaling

Principal Solutions Architect – Core & Signaling

Mountain View, CA

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.

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 3

GPP 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.

• 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.
• 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.
• 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:
• Registration and Attach
• 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:
• Diameter
• SCTP
• GTP‑C / GTP‑U
• 3
  
  GPP signalling procedures
• Technical Documentation & Standards
• Develop and maintain the Skylo technical architecture repository.
• Translate complex 3
  
  GPP and NTN architecture concepts into actionable guidance for internal engineering teams.
• Author and maintain key technical documentation including:
• Interface Control Documents (ICDs)
• High‑Level Designs (HLDs)
• 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…