Senior Back End () Engineer (with AI Voice Agent experience)

We are looking for an experienced Engineer to build a critical business feature: a real-time AI Voice Agent capable of autonomous outbound calling. This is a technical product ownership role where you will architect the system from the ground up using .

You will be responsible for solving the hard problems of voice AI: latency optimization handling user interruptions (barge-in) and noise cancellation. You will lead the implementation of our first non-English language (Dutch) working alongside native speakers for quality validation and design the architecture to support future languages.

Main Responsibilities

• Voice Agent Development (): Build and maintain the core voice agent logic using ensuring sub-second latency for a natural conversational feel.

• AI & Telephony Orchestration: Integrate Speech-to-Text (STT) LLMs and Text-to-Speech (TTS) services (e.g. Deepgram OpenAI ElevenLabs) with telephony providers (e.g. Twilio Vonage) into a seamless event-driven architecture.

• Latency & Interruption Handling: Implement sophisticated logic to handle barge-ins (when a user interrupts the bot) and silence detection ensuring the bot stops speaking immediately and listens just like a human would.

• Multi-Language Architecture: Design the codebase to support internationalization (i18n) starting with Dutch. Note: You do not need to speak Dutch; you will work with a Product Owner who handles linguistic testing.

• Infrastructure Selection: Evaluate and recommend telephony and Voice API providers if the current infrastructure is insufficient for production-grade AI voice calls.

• Expert in : Strong backend experience with particularly with WebSockets and Streams (essential for handling real-time audio data chunks).

• Voice AI Experience: Proven experience building voice bots or conversational agents. You understand concepts like VAD (Voice Activity Detection) STT/TTS latency and SIP trunking.

• API Integration: Deep experience orchestrating multiple async APIs (LLM Voice) simultaneously without blocking the event loop.

• Problem-Solving: A scars over certificates mindset. You can describe specific instances where you fixed audio quality issues reduced latency or handled edge cases in phone conversations.

We offer:

• Remote work model

• Flexible working hours

• 45 working days per year for personal time out

• Mentorship and knowledge-sharing