Voice Services Engineer

Volton Hellenic Energy SA – powering Greece with Electricity, Natural Gas, and Telecommunications through Orizon.

We provide reliable solutions and build trusted relationships with our customers.
Through innovative services, we meet today's energy demands while preparing for the challenges of tomorrow.

As Greece's first multi-service provider, we seamlessly combine energy and telecoms, creating a unique ecosystem of value and convenience to our customers.

Recognized for a 2nd consecutive year as a Great Place to Work, we are proud of our people and our culture of excellence.

We are not just keeping up with the future – we are leading the way, setting the standard, and shaping what comes next. 

Join Us

As part of its development Volton strengthens its human resources in Athens and seeks a Voice Engineer.

Responsibilities

• Design, develop and operate network nodes supporting: Mobile voice & SMS services, Fixed voice services, Online charging systems
• Specify and document engineering, operations and change management procedures
• Participate in the change management process for live network configuration changes
• Test, verify and accept new software versions, functionalities and services
• Assist in troubleshooting resolving network emergency incidents
• Provide 2nd level support for network and subscriber-related problems
• Manage suppliers and subcontractors delivering products and services related to the mobile and fixed core network
• Participate in projects related to voice services
• Collect marketing, technology and security requirements for SIM card development and updates
• Manage the SIM card lifecycle, from the supply chain to their operation in the company's network
• Manage and operate systems and applications related to SIM cards and mobile terminals (Over-the-Air, eSIM and Device Management) in cooperation with suppliers and subcontractors
• Test mobile handsets and terminals to ensure compatibility with the company's network

Requirements

• Minimum of 3 years of experience in voice services or a similar role
• University Degree in Telecommunications, Electrical/Electronic Engineering, IT or a related field
• Solid understanding of voice network architecture and services (Voice, SMS, VoLTE)
• Experience with IMS core nodes (e.g., CSCF, TAS, HSS) and related interfaces
• Hands on involvement voice core nodes (e.g., GMSC, HLR, SBC, SMSC) and related interfaces
• Understanding of SIM/eSIM technologies
• Knowledge of JavaCard technology
• Familiarity with Cloud & Virtualization (NFV) technologies
• Experience in terminal management projects (smartphones, CPEs) and their supply chain will be considered an asset
• Knowledge of architectures and specifications of Over-The-Air & Mobile Device Management applications
• Good understanding of IP networks and related protocol

Personal Skills

• Excellent analytical and communication skills
• Strong team spirit and collaboration
• Problem-solving mindset with the ability to resolve issues quickly and effectively
• Fluency in English, both oral and written

Benefits

• A competitive fixed salary package aligned with your experience and expectations
• Hybrid working model
• Private insurance, corporate benefits and perks
• Continuous training and professional development
• Excellent professional environment
• Modern and productive working facilities

Don't miss the chance to join a Great Place to Work–Certified company that fosters a positive work environment and is proudly recognized as a Best Workplace for Women 2025. Embracing an Employee First culture, we put people at the heart of everything we do; an approach honored with a Silver Award for Employee-Centric Culture and a Silver Award for Best Onboarding Initiatives.

All applications will be treated with confidentiality. If your CV meets the requirements of the job, we will contact you by phone to schedule an appointment. Information about the company on our site