Sr. Voice IMS Engineer

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.

What you’ll do

• Ensure the stable, secure and uninterrupted operation of Voice Core IMS services by delivering 2nd-level operational support, incident and problem management, and preventive and corrective maintenance across current and future voice technologies. 
• Configure, administer, upgrade and expand fixed and mobile voice systems, including software and hardware lifecycle activities, while supporting service continuity and network availability. 
• Troubleshoot complex signalling, call-control, media and service issues using protocol traces, logs, alarms, counters and end-to-end call-flow analysis; own structured root-cause investigations through resolution. 
• Test, verify and accept new systems, software releases, functionalities, integrations and services before production introduction, ensuring the quality and success of changes and upgrades. 
• Monitor fault, performance and capacity indicators, identify service degradation, and implement corrective, optimization and measurable service-improvement actions. 
• Coordinate technical escalations with vendors and internal engineering, service and security teams; support customer-impacting investigations, complaints and major incidents until closure. 
• Implement operational changes in line with security, compliance and change-management standards, and contribute to technical projects, interconnections, documentation, automation and process improvement. 
• Participate in the standby scheme and provide 24x7 support when required, including planned activities outside regular working hours. 

Who you are

• Bachelor’s or Master’s degree in Telecommunications, Electrical/Electronic Engineering, Computer Engineering or a related engineering field. 
• At least 3 years of relevant experience in the operation, support, integration or engineering of mobile Voice Core IMS systems. 
• Strong practical knowledge of IMS and Voice Core functions, including call session control, application and service platforms, subscriber and routing functions, interconnection and media-control components. 
• Strong understanding of voice services across mobile, fixed and IP domains, including VoLTE/VoWiFi, VoNR, IMS interworking, CS voice and legacy signalling where applicable, with the ability to interpret complex protocol traces and call flows. 
• Strong practical knowledge of telecom signalling protocols and interfaces, including SIP Diameter, ISUP, H.248, MAP, SCCP, and TCAP, with the ability to analyse signalling procedures, and troubleshoot complex call flows and resolve interoperability issues across IMS, IP and legacy network domains. 
• Proven troubleshooting capability in live telephony systems and networks, combined with experience in incident ownership and fault, performance, configuration and change management. 
• Good working knowledge of IP networking and Linux-based systems; exposure to virtualization or cloud-native telecom platforms, containers, orchestration, scripting, automation, monitoring and data-analysis tools is an advantage. 
• Experience with IMS service platforms, multi-vendor environments, interconnects, emergency services, number portability, roaming, regulatory requirements or geographically distributed teams is highly valued. 
• Strong analytical & problem-solving skills and effective collaboration. 
• Very good written and spoken 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

• Award-winning work environment -certified #1 Top Employer in Greece
• Competitive pay, bonus & remuneration package
• Private Health & Medical Insurance
• Hybrid way of working: a blend of remote and office-based working, including the option to work from abroad
• Unlimited access to learning resources and trainings
• Vodafone Parental Leave: 16 weeks of fully paid parental leave to all employees regardless of gender, sexual 
  orientation or length of service
• Spirit of Vodafone Day: one day each quarter dedicated to your personal development
• Extra days off: Vodafone Day, Family Day, Volunteering Day
• Office amenities (subject to the office location): such as restaurant, beauty corner, gym and parking
• Special employee offers and discounts

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 for guidance.

Together we can.