Synthflow AI is an enterprise AI agent platform that unifies customer operations across voice, chat, and messaging. Our agents handle routine interactions at scale so teams can focus on high-value work.
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Over 20M hours of operations automated
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60% more calls answered vs. non-AI operators
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150M interactions handled, 99.99% uptime
Backed by Accel, Atlantic Labs, and Singular. Trusted by 1,000+ customers. Recognized as one of the most promising companies in Germany.
LEAD VOIP ENGINEER (FREESWITCH & KAMAILIO)
Location: Berlin/Remote
Job Type: Full-Time
Experience Level: Senior
ABOUT THE ROLE
We are seeking an experienced VOIP Engineer with a strong background in FreeSWITCH and Kamailio to join our team. The ideal candidate will have extensive experience in SIP-based communications, RTP streaming, and conferencing solutions, along with a deep understanding of high-load production environments. You will be responsible for designing, implementing, and optimizing scalable VOIP solutions while ensuring high availability and performance.
RESPONSIBILITIES
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Design, deploy, and maintain FreeSWITCH and Kamailio-based VoIP solutions.
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Configure and troubleshoot SIP protocols, RTP streams, and media gateways.
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Monitor and optimize high-load production FreeSWITCH and VOIP systems.
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Implement and manage SIP monitoring tools like Homer or other real-time debugging solutions.
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Develop and fine-tune call routing, failover mechanisms, and load balancing strategies.
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Ensure security, scalability, and redundancy in the VoIP infrastructure.
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Troubleshoot and resolve VoIP-related issues in production environments.
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Collaborate with development, DevOps, and support teams to improve system performance.
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Work with SIP Trunks, SBCs (Session Border…