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 every day 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.

Position Overview

Our Global Voice Team is looking for a committed, experienced VoIP Engineer who is passionate about creating high-performing, scalable, and resilient mission-critical services that are the foundation of Five9’s next-generation CCaaS voice platform.

As a member of the team, you will play a key role in shaping the architecture and future of our voice core solution.

Responsibilities

• Participate in the design and definition of the Proxy Servers architecture for the CCaaS voice core solution
• Write clean, maintainable code and automated tests for the Proxy Servers
• Participate in an Agile Scrum team that practices DevOps
• Ensure services are scalable, resilient, and performant while running in the public cloud

Required Skills

• 3+ years of professional experience in VoIP and software development
• Deep knowledge and hands-on experience with OpenSIPS or Kamailio open-source software
• Expert-level knowledge of real-time communications signaling and media protocols (SIP, RTP, etc.)
• Ability to methodically troubleshoot complex, distributed voice systems
• Excellent communication and organizational skills, with a strong sense of ownership

Technical Skills

• OpenSIPS
• Kamailio
• SIP, RTP
• VoIP
• Proxy Servers
• CCaaS
• Cloud Platforms (AWS / Azure / GCP)
• CI/CD
• Containers
• SRE principles
• Scripting languages (Python, Bash, etc.)
• Go