Graduate Engineer, Network Solutions

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. HOW YOU WILL IMPACT SKYLO Skylo is looking for a graduate engineer to join our Protocol Stack team, working on 5G NR-NTN upper-layer and core interface protocols. You'll learn to build, integrate, and validate the PDCP, eGTP, Xn, and NGAP (N2/N3) software that connects Skylo's NTN vRAN to mobile operator core networks — working alongside our Core Network, MNO integration, and systems teams. You'll be mentored by senior engineers, but the work is real: what you build carries live traffic between our satellite network and our MNO partners' cores. WHAT YOU'LL DO - Write and maintain C++ code across our 5G NR upper-layer and core interface protocols — PDCP, eGTP-U/C, XnAP, and NGAP — starting with well-scoped modules and growing into larger components - Learn and contribute to NTN-specific PDCP adaptations: extended sequence number space, reordering timer adjustments for long propagation delay, lossless handover support, and PDCP status reporting - Support eGTP-U tunnelling work for the N3 user plane: GTP-U path management, echo/error indication handling, end-marker procedures, and QoS flow-to-DRB mapping - Contribute to Xn interface procedures (XnAP): Xn Setup, UE context retrieval, handover preparation, and NG-RAN node configuration update - Contribute to NGAP procedures over N2: Initial UE Message, UE Context Setup/Modification/Release, paging, and handover signalling - Build test cases, simulation harnesses, and automation to validate interface behaviour against 3GPP specifications - Support Core Network and MNO integration teams in validating NGAP procedures against commercial and lab AMF implementations - Help validate Xn/N2/N3 interfaces end-to-end across gNB-CU-CP, gNB-CU-UP, and core network elements in a disaggregated vRAN architecture - Debug and root-cause interface-layer issues using packet capture and protocol analysis tools — Wireshark, tcpdump, custom dissectors, GDB, and log analysis. This is where you'll build the instincts that define strong protocol engineers. - Learn to read 3GPP Rel-17/18 NR-NTN specifications (TS 38.413, TS 38.423, TS 29.281, TS 38.323) and translate them into software requirements, with guidance from systems engineers - Participate in code reviews, architecture discussions, and technical documentation - Use AI coding assistants (Claude, Cursor, Codex) across the development lifecycle — from spec interpretation and boilerplate generation to test automation and code review — and help shape how the team works with them SOUND LIKE YOU? WHAT YOU BRING Essential - Strong programming ability in C++ — you've written non-trivial C++ (university projects, internships, open source, or personal work) and understand memory management, pointers/references, and the standard library. This is our top priority. - Bachelor's, Master's, or PhD in Electrical Engineering, Wireless Communications, Telecommunications, Computer Science, or a closely related field - Working knowledge of networking and communications fundamentals: the protocol stack model, IP, UDP/TCP, tunnelling, and packet-based signalling - Familiarity with 5G or LTE architecture from coursework, projects, or research — RAN vs. core, control plane vs. user plane, and what a handover involves - Comfortable working in Linux and with version control (Git) - Curiosity and persistence when debugging: you enjoy chasing a problem through a packet capture until you understand the root cause - Willingness to work