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Working at Vodafone

  • Company employees
    85,887

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Join Vodafone as a Voice Core Engineer in Lisboa, Portugal. In this hybrid role, you will lead the technical design, integration, and delivery of Voice Core solutions across CS, IMS, and 5G domains, guiding junior engineers and collaborating with international teams.

Requirements

  • University degree in Telecommunications, Computer Science, Electronics, or equivalent.
  • Expertise in CS, IMS, and 5G Voice Core architectures and 3GPP standards.
  • Understanding of telecom protocols and call flows such as SIP, Diameter, SS7, and MAP.
  • Experience with inter-functional integrations between network elements and IT systems.
  • Fluency in English.
  • Experience in a similar Voice Core engineering or delivery role is preferred.

Skills & Responsibilities

  • Voice Core Architectures: Design, integrate, and deploy Voice Core solutions like MSS/MGW, SBC, CSCF, HSS, and 5G network functions.
  • Signaling and Protocols: Utilize protocols including SIP, Diameter, SS7, and HTTP2 to manage call flows and ensure system interoperability.
  • Technical Leadership: Guide, mentor, and technically coach junior engineers while collaborating with cross-functional stakeholders.
  • Project Delivery: Plan, execute integration and acceptance testing, and prepare Work Orders for Change Management.
  • Potential transition routes: People from Network Engineering or Telecom Operations roles may bring relevant networking and signaling skills, alongside meeting telecommunications degree requirements.

Job description

Join Us

At Vodafone, we’re not just shaping the future of connectivity for our customers – we’re shaping the future for everyone who joins our team. When you work with us, you’re part of a global mission to connect people, solve complex challenges, and create a sustainable and more inclusive world. If you want to grow your career whilst finding the perfect balance between work and life, Vodafone offers the opportunities to help you belong and make a real impact.

The Voice Core Engineering & Delivery Engineer plays a critical role in the design, delivery, and evolution of Voice Core solutions across Vodafone Operating Companies. Acting as a technical authority, this role supports technical analysis (e.g., RFQs, High-Level Designs, and solution evaluations) and contributes to end‑to‑end Voice Core architectures that span multiple markets.

The role combines deep hands‑on engineering with technical leadership. The Engineer is also expected to guide, mentor, and technically coach other junior engineers while ensuring high‑quality integration, testing, and delivery of complex Voice Core information systems within CS, IMS and 5G domains, in line with 3GPP standards and Vodafone global architecture principles.

What you’ll do

  • Lead the technical design and specification of Voice Core hardware and software solutions in alignment with customer requirements and Vodafone global standards;
  • Perform integration, deployment, and expansion of Voice Core information systems, including but not limited to MSS/MGW, STP, DRA, HSS, HLR, SBC, CSCF, TAS, UDR, AUSF, UDM, IBCF;
  • Execute and coordinate integration and acceptance testing for new software releases, ensuring backward compatibility and seamless coexistence with existing platforms;
  • Actively contribute to low‑level design specifications, solution documentation, and implementation guidelines for new Voice Core functionalities and services;
  • Support end‑to‑end project delivery, including planning, technical coordination, risk identification, and progress reporting for complex Voice Core projects;
  • Define and prepare Work Orders to support Change Management and Operations teams;
  • Provide technical leadership and on‑the‑job training, accelerating the competence development of junior engineers within the Voice Core domain;
  • Collaborate with cross‑functional stakeholders (architecture, operations, vendors, and customer teams) to improve service quality, network reliability, and customer experience.

Who you are

  • University degree in Telecommunications, Computer Science, Electronics, or equivalent;
  • Broad awareness of telecommunications and cloud ecosystems, including transport, IP networking, and system interoperability;
  • Experience with inter‑functional integrations between network elements, IT systems, and operational platforms;
  • Expertise in CS, IMS and 5GVoice Core architectures and information systems as defined by 3GPP standards;
  • Understanding of telecom protocols and call flows, including SIP, Diameter, SS7, MAP and related signaling technologies. Complementary protocols including HTTP2, JSON, SOAP, REST, TLS, SQL;
  • Basic knowledge of the software and system lifecycle, including design, development, integration, testing, acceptance, deployment, and optimization;
  • Experience in a similar Voice Core engineering or delivery role is a plus;
  • Ability to work effectively in virtual, international teams and to communicate complex technical topics clearly to diverse audiences;
  • Fluency in English.

Not a perfect fit?

Worried that you don’t meet all the desired criteria exactly? At Vodafone we are passionate about empowering people and creating a workplace where everyone can thrive, whatever their personal or professional background. If you’re excited about this role but your experience doesn’t align exactly with every part of the job description, we encourage you to still apply as you may be the right candidate for this role or another opportunity.

What's in it for you

  • Hybrid Work Model - Flexible hybrid work model with 8-10 in-office days per month, managed by team leaders;
  • Vodafone Products and Services - Employees get a mobile phone, free communication plan, data card, and various discounts on services and products;
  • Recognition - Recognition programs for innovative, creative, high-potential employees and exemplary behaviors;
  • Health and Well-being - Well-being Program offers nutrition and psychological consultations, webinars, workshops, and discounts on various services and products;
  • Learning - Access to Communities of Practice and a customizable digital training platform with high-quality content (namely Harvard Business Publishing, Skillsoft and Speexx);
  • Local and International Mobility - Internal recruitment with local and international rotation opportunities across departments and roles.

Who we are

We are a leading international Telco, serving millions of customers. At Vodafone, we believe that connectivity is a force for good. If we use it for the things that really matter, it can improve people's lives and the world around us. Through our technology we empower people, connecting everyone regardless of who they are or where they live and we protect the planet, whilst helping our customers do the same.

Belonging at Vodafone isn't a concept; it's lived, breathed, and cultivated through everything we do. You'll be part of a global and diverse community, with many different minds, abilities, backgrounds and cultures. ;We're committed to increase diversity, ensure equal representation, and make Vodafone a place everyone feels safe, valued and included.

If you require any reasonable adjustments or have an accessibility request as part of your recruitment journey, for example, extended time or breaks in between online assessments, please refer to https://careers.vodafone.com/application\-adjustments/ for guidance.

Together we can.

Apply now
Vodafone

Voice Core Engineer

Lisbon
Hybrid

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