Software Engineer III – VoIP / FreeSWITCH

We're looking for an experienced FreeSWITCH Developer / VoIP Software Engineer to design, develop, and maintain the telephony solutions that power Vonage's call processing platform. You'll build real-time voice communication systems that handle millions of calls, developing features like call processing, recording, voicemail, conferencing, and external service integrations. This is a critical role where your work directly impacts business communications for customers worldwide.

Core Responsibilities

• Build scalable telephony systems — Design and develop distributed, high-volume production telephony applications for our UCaaS platform that handle real-time voice traffic at scale
• Develop custom FreeSWITCH solutions — Create custom modules, dialplan configurations, and ESL (Event Socket Library) integrations for advanced call control and automation
• Deliver advanced telephony features — Implement call recording, voicemail transcription, fax processing, audio streaming, and other mission-critical voice features
• Rapid prototyping to production — Build proof-of-concepts quickly and evolve them into production-ready, maintainable code
• Drive technical innovation — Evaluate emerging telephony technologies and recommend architectural improvements that enhance our platform capabilities
• Mentor and lead — Guide team members on design patterns, best practices, and telephony architecture decisions

Day-to-Day Collaboration

• Participate in the full agile development lifecycle: sprint planning, design reviews, standups, and demos
• Respond promptly to production incidents affecting customers and business operations
• Work independently on end-to-end feature delivery while contributing to broader team goals
• Partner closely with Product Management, QA, and Operations teams to deliver cohesive solutions
• Communicate progress, blockers, and technical decisions clearly with engineering leadership

Required Experience & Skills

Telephony & VoIP Expertise (Must-Have)

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