Voice Core Engineer

Vodafone; Lisboa; Hybrid; EUR 55,000 - 75,000; Full time

Benefits offered by this job

Hybrid Work Model

Vodafone products & services discounts

Recognition program

Well-being program

Learning platform access

Mobility opportunities

Job summary

Vodafone seeks a Voice Core Engineering & Delivery Engineer to design, deliver and evolve Voice Core solutions across Vodafone markets. You will guide junior engineers, ensure high-quality testing, and align with 3GPP standards in CS, IMS and 5G domains.

Role combines hands-on engineering with technical leadership, mentoring, and collaboration with architecture, operations, vendors, and customer teams to improve service quality and reliability.

Qualifications

• University degree in telecommunications, computer science, electronics, or equivalent.
• Experience with CS, IMS and 5G Voice Core architectures and information systems per 3GPP standards.
• Understanding of telecom protocols and call flows (SIP, Diameter, SS7, MAP) and related tech.

Responsibilities

• Lead the technical design and specification of Voice Core hardware and software solutions in alignment with Vodafone global standards.
• Perform integration, deployment, and expansion of Voice Core information systems (MSS/MGW, STP, DRA, HSS, HLR, SBC, CSCF, TAS, UDR, AUSF, UDM, IBCF).
• Coordinate integration and acceptance testing for new software releases with backward compatibility.
• Contribute to low-level design specs, solution docs, and implementation guidelines for new Voice Core features.
• Support end-to-end project delivery: planning, coordination, risk identification, progress reporting.

Skills

Voice Core

Engineering

3GPP knowledge

SIP

Diameter

5G

Cloud ecosystem awareness

Interfunctional collaboration

English fluency

Education

University degree in Telecommunications/CS/Electronics

Tools

MSS/MGW

HSS/HLR

SBC

CSCF

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

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.