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 – including its own owned and operated global mobile core network, fully fledged in-house developed eSIM technology, and an extensive portfolio of telecom licenses – 1GLOBAL operates as a fully regulated telecommunications provider across 40 countries worldwide.

We serve many of the world’s leading banks, enterprises, and digital-first businesses, including neo-banks, global fast moving consumer goods companies, travel leaders, and payment service providers. Today, 1GLOBAL connects more than 70 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. Recent years have marked a defining phase in our journey, with major enterprise and mass-consumer client wins accelerating our 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 . We operate as a fully regulated Mobile Virtual Network Operator (MVNO) in 12 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, our team of close to 500 experts across 15 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-haves

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-haves

+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 telecommunications companies, expanding over 100% year-on-year under the leadership of successful tech entrepreneurs.
Major Transaction Exposure: Be in the driver’s seat for transactions that will have an impact on the future telco industry.
Work with a Talented Team: From the Board and the Founders to the Senior Management Team, you will collaborate daily with the most capable and renowned external advisors, and constantly being exposed to talented and driven individuals.
Dynamic Work Environment: Thrive in a collaborative, fast-paced workplace where innovation is encouraged, and every contribution counts.
Professional Development: Work alongside industry experts to enhance your skills and knowledge in a cutting-edge field.
International Experience: Gain opportunities to work in different 1GLOBAL offices around the world as you grow within the company.
Open Communication Culture: Join a team where your ideas are heard, and open dialogue is encouraged, fostering a supportive and transparent work environment.
Get Things Done Attitude: Be part of a results-driven team that values efficiency, creativity, and the drive to make a tangible impact in the industry.

1GLOBAL is an equal opportunity employer, we value your character as much as your talent. Diversity drives our innovation, and we offer a collaborative, dynamic, and international work environment. We are excited for you to join our mission to revolutionise connectivity globally.

Voice and Services Engineer - Lisbon Based