Lead VOIP Engineer

Vor 6 Tagen

Berlin, Berlin, Deutschland Synthflow AI Vollzeit 80.000 € - 120.000 € pro Jahr

Synthflow AI is a
no-code platform for deploying voice AI agents
that automate phone calls across contact center operations and business process outsourcing (BPO) at scale. We help mid-market and enterprise companies manage routine calls to save teams time and resources.

Our agents have already delivered measurable impact:

  • Over 5 million hours of contact center operations saved
  • 35% more calls answered compared to non-AI operators
  • 45 million calls handled with a 99.9% uptime

Backed by
Accel, Atlantic Labs, and Singular
and trusted by over 1,000 customers, our growth leads an industry shift toward sophisticated and accessible conversational AI.

*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

  • Design, deploy, and maintain FreeSWITCH and Kamailio-based VoIP solutions.
  • Configure and troubleshoot SIP protocols, RTP streams, and media gateways.
  • Monitor and optimize high-load production FreeSWITCH and VOIP systems.
  • Implement and manage SIP monitoring tools like Homer or other real-time debugging solutions.
  • Develop and fine-tune call routing, failover mechanisms, and load balancing strategies.
  • Ensure security, scalability, and redundancy in the VoIP infrastructure.
  • Troubleshoot and resolve VoIP-related issues in production environments.
  • Collaborate with development, DevOps, and support teams to improve system performance.
  • Work with SIP Trunks, SBCs (Session Border Controllers), and Media Servers.
  • Implement WebRTC-based voice and video solutions.
  • Document system configurations, troubleshooting guides, and best practices.

Requirements

  • 5+ years of experience in VOIP engineering, particularly with FreeSWITCH and Kamailio.
  • 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.
  • Strong problem-solving skills and ability to work in highly available and scalable environments.

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 VOIP Engineer

    vor 1 Woche

    Berlin, Berlin, Deutschland Synthflow AI Vollzeit 80.000 € - 120.000 € pro Jahr

    Synthflow AI is a no-code platform for deploying voice AI agents that automate phone calls across contact center operations and business process outsourcing (BPO) at scale. We help mid-market and enterprise companies manage routine calls to save teams time and resources. Our agents have already delivered measurable impact:Over 5 million hours of contact...

  • Embedded Software Engineer Audio/VoIP

    vor 2 Wochen

    Berlin, Berlin, Deutschland Valentum Engineering GmbH Vollzeit 60.000 € - 100.000 € pro Jahr

    Valentum Engineering has its roots in the automotive industry. After successfully establishing ourselves as a development partner for well-known vehicle manufacturers, automotive suppliers and system suppliers, numerous customers from other industries now also rely on our support. We are active in all development phases - from specification to...

  • Lead Software Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo Vollzeit 90.000 € - 160.000 € pro Jahr

    Your Mission As Lead Platform Engineer at hallo theo, you build and maintain the core infrastructure and platform services that enable scalable, reliable deployment and operation of our products. You own cloud infrastructure, system design and development enablement so that product and data teams can ship quickly, safely and in a compliant way. In this...

  • Lead Software Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo Vollzeit 80.000 € - 120.000 € pro Jahr

    Your MissionAs Lead Platform Engineer at hallo theo, you build and maintain the core infrastructure and platform services that enable scalable, reliable deployment and operation of our products. You own cloud infrastructure, system design and development enablement so that product and data teams can ship quickly, safely and in a compliant way. In this senior...

  • Lead Software Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo Vollzeit 120.000 € - 140.000 € pro Jahr

    Your Mission As Lead Platform Engineer at hallo theo, you build and maintain the core infrastructure and platform services that enable scalable, reliable deployment and operation of our products. You own cloud infrastructure, system design and development enablement so that product and data teams can ship quickly, safely and in a compliant way. In this...

  • Lead Software Engineer

    vor 23 Stunden

    Berlin, Berlin, Deutschland Acta Vollzeit 70.000 € - 120.000 € pro Jahr

    Looking for a Lead Software Engineer at ActaWTF is Acta?Acta is Latin for "act" – as inActa non verba: act, don't talk.Founded by:Louis Morgner – founder of Jamie AI (millions in revenue)Bjoern Keune – founder of Invincible Brands (€400M exit)(they might know a thing or two about building companies)Instead of one product, we're building an...

  • VoIP-Experte (all genders)

    vor 2 Wochen

    Berlin, Berlin, Deutschland DATAGROUP SE Vollzeit 60.000 € - 80.000 € pro Jahr

    DATAGROUP in BerlinDATAGROUP ist einer der führenden deutschen IT-Dienstleister – dank unseres engagierten Teams. Unsere Leidenschaft für Technologie und Innovation ermöglicht es uns, unseren Kunden verlässliche IT-Services zu liefern. Bei uns erwartet Dich ein fesselndes und anspruchsvolles Aufgabengebiet in einem innovativen Unternehmen. Eine offene...

  • Lead Product Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo Vollzeit 95.000 € - 115.000 € pro Jahr

    Your Mission As Lead Product Engineer at hallo theo, you design, build and ship scalable product solutions that power our platform. You own critical user journeys end-to-end – from early discovery with Product and Design, through technical design and implementation, all the way to rollout, quality and iteration based on data and customer feedback. You act...

  • Lead Product Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo Vollzeit 80.000 € - 120.000 € pro Jahr

    Your Mission As Lead Product Engineer at hallo theo, you design, build and ship scalable product solutions that power our platform. You own critical user journeys end-to-end – from early discovery with Product and Design, through technical design and implementation, all the way to rollout, quality and iteration based on data and customer feedback. You act...

  • Lead Product Engineer

    Vor 6 Tagen

    Berlin, Berlin, Deutschland hallo theo München GmbH Vollzeit 50.000 € - 120.000 € pro Jahr

    Your MissionAs Lead Product Engineer at hallo theo, you design, build and ship scalable product solutions that power our platform. You own critical user journeys end-to-end – from early discovery with Product and Design, through technical design and implementation, all the way to rollout, quality and iteration based on data and customer feedback. You act...