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. Over 20M hours of operations automated 60% more calls answered vs. non-AI operators 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. We’re looking for a hands-on VoIP Engineer to help build, maintain, and improve our telephony infrastructure, with a focus on Kamailio and RTPEngine. You’ll work on SIP routing, media handling, and production troubleshooting to keep our voice services reliable and performant. This role is a good fit for someone with practical Kamailio and RTPEngine experience, working knowledge of FreeSWITCH, and strong Linux and SIP/RTP debugging skills. Your Responsibilities Deploy, configure, and maintain Kamailio and RTPEngine Troubleshoot SIP signaling, RTP media, and call quality issues Support FreeSWITCH services and Linux-based telephony infrastructure Improve call routing, load balancing, failover, and monitoring Manage configurations in Git and document operational changes What We’re Looking For Hands-on experience with Kamailio and RTPEngine Strong SIP/RTP debugging skills using tools like sngrep, tcpdump, or Wireshark Working knowledge of FreeSWITCH Solid Linux administration and networking skills Experience with Git and collaborative change management Nice to have: GCP, Kubernetes, Python or Go, and Bash scripting Founded in Berlin in 2023 by serial entrepreneurs Albert Astabatsyan, Hakob Astabatsyan, and Sassun Mirzakhan-Saky, Synthflow AI democratizes access to advanced voice AI with a no-code platform that lets enterprises easily create, deploy and scale natural-sounding, cost-effective voice agents tailored to their business needs.

Lead/Senior VoIP Engineer