Telecom Engineer I - Voice Delivery Engineer

Join us in bringing joy to customer experience. Five9 is a leading provider of cloud contact center software, bringing the power of cloud innovation to customers worldwide. Living our values everyday results in our team-first culture and enables us to innovate, grow, and thrive while enjoying the journey together. We celebrate diversity and foster an inclusive environment, empowering our employees to be their authentic selves. The Telecom Engineer I is a specialized engineering professional responsible for building, testing, and maintaining the voice solutions that power the customer voice integrations and Five9 cloud contact center platform. Key Responsibilities A Five9 Telecom Engineer I focuses on the customer facing voice SIP trunk builds, architecture and operation of real-time communication systems, which includes: Developing high-quality, reliable, and high-performing voice applications across various platforms (desktop, web). Working with key technologies such as SIP, MPLS and VPN. Designing and optimizing low-latency voice pipelines and handling real-time streaming voice (RTP/SIP). Troubleshooting and resolving complex issues within the global voice platform. Collaborating with cross-functional teams (Product Managers, Global Solution Architects and Connectivity PMs) to deliver a seamless customer experience. Ensuring the platform is scalable, reliable, observable, and maintainable, following DevOps practices. Mentoring and training junior team members. Required Skills and Qualifications Typical requirements for a voice engineering role at Five9 include: Experience: 5+ years of industry experience in software development and troubleshooting VoIP systems. Technical Expertise: Expert-level knowledge of SIP call flows, routing algorithms, and carrier interoperability. Strong hands-on experience with real-time voice systems in C++, Java, or JavaScript. Ribbon SBC (5k, 7k, SWe), GSX (9000) Networking Knowledge: Deep understanding of telecommunication protocols (