Lead VOIP Engineer (FreeSWITCH & Kamailio)
Synthflow AIBerlin, Germany
Posted November 4, 2025
Full Time
About the Company
Synthflow AI is a no-code platform specializing in deploying voice AI agents to automate phone calls across contact center operations and business process outsourcing (BPO) for mid-market and enterprise companies. As a G2 Grid Leader for AI Agents, Synthflow enables efficient management of routine calls, saving teams time and resources without the need for additional headcount.
Job Description
Synthflow AI is an enterprise AI agent platform that unifies customer operations across voice, chat, and messaging. We are seeking an experienced VOIP Engineer with a strong background in FreeSWITCH and Kamailio to join our team.
Requirements
- 5+ years of experience in VOIP engineering, particularly with FreeSWITCH and Kamailio.
- 3 years of experience with k8s on production systems is a must have.
- Strong expertise in SIP protocol, RTP streaming, and VoIP call flows.
- Experience working in high-load production FreeSWITCH environments.
- Hands-on experience with Homer SIP capture or similar SIP monitoring tools.
- Deep understanding of NAT traversal, STUN/TURN, WebRTC, and ICE frameworks.
- Strong knowledge of load balancing, failover strategies, and traffic optimization.
- Proficiency in Linux administration, networking, and troubleshooting.
- Experience with database integration (Redis, PostgreSQL, or NoSQL solutions).
- Familiarity with WebRTC, Asterisk, OpenSIPS, or RTP Proxy is a plus.
- Ability to write Bash/Python (or Golang) scripts for automation and monitoring.
Benefits
- Unspecified benefits
