About Us 1GLOBAL is a technology-driven global mobile communications provider, delivering global connectivity solutions to enterprises and consumers. Powered by a best-in-class telecom platform with its own owned and operated global mobile core network in 15 countries, fully fledged in-house developed eSIM technology, and an extensive portfolio of telecom licenses; 1GLOBAL operates as a fully regulated telecommunications provider across 43 countries worldwide. The company serves many of the world’s leading banks, multinational enterprises, global retailers and digital-first businesses, including neo-banks, global fast moving consumer goods companies, travel leaders, and payment service providers. Today, 1GLOBAL connects more than 80 million people and devices globally, enabling our customers to launch, scale, and innovate with confidence in the mobile ecosystem. 1GLOBAL is a profitable, fast-growing business. With full-year revenues in 2025 exceeding US$200 million and profits of over US$25 million, we generate strong cash flows to fund our growth allowing us to continuously invest in infrastructure, platform innovation, and global expansion. In 2026 also the parent of the Lidl Group acquired a 10% interest in 1GLOBAL as part of a deal for Lidl to offer globally to its 180 million consumers communication services. Recent years have marked a defining phase in 1GLOBAL’s journey, with major enterprise and mass-consumer client wins accelerating its evolution into a global mobile connectivity powerhouse, purpose-built to enable consumer brands to enter and succeed with their own aspirations to offer telecommunications services to their clients. Founded in 2022 by experienced technology entrepreneurs, Hakan Koç and Pyrros Koussios, 1GLOBAL has rapidly emerged as a European technology leader shaping the future of global telecommunications. It operates as a fully regulated Mobile Virtual Network Operator (MVNO) in 15 countries and as a regulated telecom operator in an additional 28 markets. Headquartered in the Netherlands, with world-class R&D hubs in Lisbon, Berlin, and São Paulo, its team of close to 550 experts across 16 countries is united by a single ambition: to redefine global mobile connectivity through technology, scale, and execution excellence. About the Team As a Network Engineering member, in the Voice and Services functional area, you will be responsible to propose, analyze and define the requirements for new and existing services and systems, related with the voice systems under the responsibility of the functional area. Prepare, design, test and provide new solutions or product changes of the already existing portfolio. Define and support the technology evolution roadmap for the systems under the functional area. Participate and support the other functional areas in cross functional projects. About the Role Collaboration with other Networks teams in defining and managing the projects for delivery of new solutions Project delivery. Network design. Integration and migration strategy definition. Collaboration with other relevant departments. Responsible for end-to-end delivery Design of new consumer and corporate telecom solutions Creation of technical documentation (HLD’s, LLD’s, WO’s, etc.) and maintain it over the lifecycle of the solutions Perform implementations in live environment. Understanding of End to End system testing requirements Follow-up and define Quality and Performance indicators Capacity and Performance Analysis, Reporting and Improvement Solution Definition Service & Resource configuration definition and implementation on requested systems Work on complex solutions that influence the design of current products and addresses design issues for future products or technologies Close relationship with external partners like carriers, service providers Elaborate, and manage the process, for change requests to current partners in order to meet the network necessities Control the network elements roadmap, being responsible for the necessary software/hardware upgrade during the components lifecycle Generate and implement process improvements, including and especially cross-team processes Documents the existing technology portfolio and proposes recommendations for improvements and/or alternatives Requirements About You Must Have Proven experience on implementation of live solutions on mobile telecom (GSM, UMTS, LTE, IMS), networks design, capacity management, engineering and architecture Knowledge of 3GPP, GSMA, ITU standards and specifications Experience in the design, test and operation of NGN based networks, including MSS/MGW, HLR/HSS, SBC Experience in defining, establishing and maintaining voice interconnects, SIP/RTP based Understanding about IMS architecture. Knowledge about VoIP, VoLTE, VoWiFi, and QoS Experience with SMS service configuration and routing IMS Architecture with understanding of IMS nodes including P/S/I-CSCF, Application Servers IMS Protocol Interfaces – Gm Interface, ISC interface, Sh Interface, Cx, SOAP/XML, etc. Experience in mobile services charging (offline, online). Knowledge and experience of OCS and, Ro, Ro+, Ga and Bp interfaces Knowledge and experience with Diameter/SCTP networks and protocol Knowledge and experience with Signaling Gateways and protocols including SS7, SIGTRAN, MAP and CAMEL Experience with protocol analyzer tools like Wireshark, Astelia, and ability to use them to troubleshoot networks errors/problems for the mentioned protocols Experience with ETSI NFV architecture and solutions Familiar with MVNO/MVNE/MVNA architecture(s) and landscape English proficiency mandatory, other languages are a plus Degree in Telecom Engineering or Computer Science or equivalent experience Nice to Have +3 years working on telecoms, designing and implementing mobile core networks Previous experience with Nokia, Oracle and Ribbon IMS products Benefits Why 1GLOBAL? Growth Opportunities: Advance your career in one of the fastest growing telecommu