Senior Full Stack Engineer, Voice Agent (IVA)

We are looking for a Senior Full Stack Engineer with strong experience in VoIP, SIP telephony, and conversational AI to join a Healthcare product.

You will help develop an intelligent voice solution that automates pharmacy calls, processes prescription-related requests, and connects patients with pharmacy staff when needed.

RESPONSIBILITIES:
Develop and improve the voice agent, including conversation flows, patient verification, fallback scenarios, and call transfers;
Build backend services and integrations with pharmacy management systems;
Maintain the telephony layer, including SIP, RTP, codecs, DTMF, and PBX integrations;
Optimize STT, LLM, and TTS pipelines for performance, accuracy, latency, and cost;
Implement monitoring, call tracing, quality evaluation, and regression testing;
Investigate production issues and contribute to architectural decisions.

REQUIREMENTS:
Senior-level experience in backend or full-stack development;
Strong knowledge of Python or TypeScript/Node.js;
Hands-on production experience with VoIP and SIP telephony;
Experience building IVR systems, voice bots, or LLM-powered voice agents;
Understanding of STT, TTS, turn-taking, tool calling, and real-time voice processing;
Experience integrating LLMs and third-party systems into production;
Working knowledge of Asterisk or a similar PBX;
Strong problem-solving, ownership, and communication skills.

WILL BE PLUS:
Experience with LiveKit Agents, Vapi, Retell, jambonz, or similar platforms;
Knowledge of Kamailio, OpenSIPS, FreeSWITCH, or MCP;
Experience in Healthcare or other security-sensitive environments;
Knowledge of React, Docker, Terraform, and observability tools.

MAIN BENEFITS:
Flexible working hours;
25 paid days off and 10 sick/medical leaves;
Additional paid days off for personal events;
Maternity/Paternity leaves;
Medical insurance;
Self-development budget;
Referral bonuses;
Corporate events and gifts;
Speaking Clubs;
PE accounting and support.