Senior Staff Engineer | AI Voice Engineering

We are looking for a Senior Staff Engineer, AI Voice Engineering, who will be responsible for the software architecture and software development of Five9’s AI Agent voice orchestration software platform. This platform handles real-time streaming voice, including RTP/SIP, integration with speech recognition engines, speech synthesis engines, end of turn model execution and interruption model inference.

As a senior individual contributor, you’ll not only be one of the most senior developers on the team, you’ll also mentor junior engineers and set technology direction for platform. You’ll work with other teams, collaborating cross-functionally to make sure complete solutions are delivered. You’ll make some of the most important technology decisions and be in the driver’s seat for the platform evolution. You’ll also get your hands dirty working direcdtly on the software, diagnosing issues, and helping uplevel the team to reach the highest levels of performance. Your responsibility extends through deployment and operations (we practice devops), and you will ensure the software platform is low latency, scalable, reliable, observable and maintainable by Five9.

What You’ll Do

Lead architecture and development of real-time AI voice systems Design and optimize low-latency voice pipelines using RTP/SIP Integrate ASR, TTS, and AI inference services Mentor engineers and lead technical best practices Collaborate with Product, AI, Infrastructure, and SRE teams Own the full lifecycle: design, development, deployment, and operations Ensure scalability, reliability, and observability

Required Qualifications

10+ years of overall software development experience 5+ years building real-time voice systems in C++ 1+ year experience with real-time GenAI voice platforms Bachelor’s or higher degree in Computer Science or related field

Technical Skills

Modern C++ (C++17+), RTP/SIP, audio codecs, SIP/SDP, ASR/TTS integration, AI APIs, cloud platforms (AWS/Azure/GCP), CI/CD, containers, SRE principles

Leadership & Impact

Lead architecture for mission-critical systems Mentor engineers and influence platform-wide decisions Balance latency, quality, cost, and reliability trade-offs

Five9 embraces diversity and is committed to building a team that represents a variety of backgrounds, perspectives, and skills.  The more inclusive we are, the better we are.  Five9 is an equal opportunity employer.