Telephony Engineer

<br><h3>Requirements</h3> <ul><li>5 to 10 years of experience in VoIP and telephony engineering</li><li>Deep understanding of SIP protocol including messaging, methods, response codes and SDP, as well as troubleshooting of signaling and media issues including NAT and RTP</li><li>Knowledge of FreeSWITCH including architecture, dialplan development using Lua or XML, configuration of SIP profiles, gateways and modules such as ESL and Sofia, and performance optimization</li><li>Experience building utilities, tools, management services for VoIP infrastructure</li><li>Experience with Go language.</li><li>Solid understanding of networking including TCP IP, RTP RTCP and traffic analysis using tools such as tcpdump, Wireshark and sngrep</li><li>Strong Linux administration (Debian or Ubuntu)</li><li><br></li></ul><p><strong>Nice to have</strong></p><ul><li>Experience with Kamailio/Opensips or rtpengine</li><li>Familiarity with CI CD, Docker, Ansible and Kubernetes</li><li>Experience with large scale telephony systems</li><li>Experience with Node.js for integration services, event socket (ESL) interaction with FreeSWITCH and REST API development</li><li>Background in voice biometrics projects</li></ul> <br><h3>Responsibilities</h3> <ul><li>Design and modernization of the telephony infrastructure</li><li>Integration with telecom providers in the US, LATAM and Europe</li><li>Optimization of resources and telecom costs</li><li>Building call handling systems from scratch for both outbound and inbound traffic</li><li>Development of integration solutions with the AI platform</li><li>Driving reliability, scaling and fault tolerance</li><li>Working with high call volumes using Kamailio/OpenSIPS and rtpengine</li><li>Participate in 2d and 3d level support duties as well as on-call rotation </li></ul> <br><h3>What we offer</h3> <ul><li><span class="ql-cursor"></span>The team has built award-winning AI products for tech corporations — devices, voice assistants, products that are actually in the world </li><li>Cutting-edge tech stack: Speech Technologies, NLP, Generative AI (LLMs, diffusion models), voice-first agentic architecture with privacy-first and on-premises deployment</li><li>High engineering bar and real ownership — the team cares about what actually works in production, not what looks good in a demo, and you'll see the impact of your work directly </li><li>Fast career progression — a senior-heavy team and a high volume of real problems means you grow faster than you would anywhere else </li><li>Startup pace with enterprise stability — real clients, real revenue, no bureaucracy </li><li>Fully remote across Europe</li><li>21 vacation days + public holidays + 5 sick days </li><li>Private English lessons via Preply</li><li>Participation in Employee Stock Ownership Plan (ESOP)</li></ul>