Voice Network Engineer

Voice Engineer (Enterprise Healthcare Environment)Location: Sofia, Bulgaria (Sofia working hours)Department: IT Infrastructure / Network EngineeringJob Type: Full-Time (initial freelance period)About the RoleWe are looking for an experienced Telecom Voice Engineer to support a large U.S.-based healthcare organisation with over 50,000 end users (growing to 65,000 after a merger). You will join a global Network Engineering team responsible for ensuring reliable and secure enterprise voice services in a mixed Cisco and Avaya environment. Work is performed during Bulgarian (Sofia) working hours, with occasional participation in change management meetings that may occur during U.S. hours when presenting planned changes. The position starts with a 2–3-month freelance (civil) contract, followed by a full Bulgarian labour contract if the cooperation is successful.During the initial period, the focus will be on reducing the existing backlog and gaining familiarity with the systems. Once established, the role will expand to include project and migration work, while continuing to handle operational support.All engineers applying for this role must be Bulgarian citizens and eligible to sign a Bulgarian labour contract.Key Responsibilities• Design, configure, and maintain voice infrastructure, including VoIP systems, PBXs, SIP trunks, and voice gateways• Troubleshoot voice quality issues, call routing problems, and system outages across Cisco and Avaya environments• Participate in the Avaya-to-Cisco migration, including incident handling, change coordination, and platform transition• Collaborate with network and system engineers to ensure voice-data integration and end-to-end reliability• Maintain system documentation, configuration files, and change records• Support unified communication platforms such as Microsoft Teams, Cisco Webex, and Zoom• Contribute to capacity planning, usage analysis, and infrastructure optimisationQualifications• Bulgarian citizenship and ability to sign a Bulgarian labour contract (mandatory)• Bachelor’s degree in Telecommunications, Computer Science, or related field• 5+ years of enterprise-level experience in voice engineering• Strong understanding of SIP, RTP, H.323, and VoIP codecs• Hands-on experience with Cisco Call Manager (CUCM) and Avaya voice systems – both required• Knowledge of Asterisk is a plus• Experience with monitoring and diagnostic tools (SolarWinds, Wireshark, RTMT)• Solid understanding of TCP/IP, routing, firewalls, and QoS for voice traffic• Ability to work in a fast-paced environment with a focus on reliability and service quality