Voice AI Engineer

NAIRON GmbH; Kreuzlingen; Remote; CHF 120,000 - 170,000; Full time

Benefits offered by this job

Flexible work setup

Company laptop and phone

Collaborative environment

Growth opportunities

Job summary

Nairon GmbH is a Swiss startup building AI voice agents that handle live calls and web interactions for businesses. We seek a senior engineer to make our agents sound fast, natural, and reliable in real-time conversations.

You will optimize latency, streaming pipelines, and prompts for efficient LM usage, while maintaining high reliability across GPUs and speech components. English is the working language; German-language data experience is a plus.

Qualifications

• Senior or strong mid-level engineer with production experience in real-time audio, conversational AI or ML model serving.
• Strong Python, including asyncio and streaming pipelines.
• Hands-on work with speech (STT, TTS, VAD) and LLM APIs in latency-sensitive systems.
• Model serving on GPUs, for example with vLLM or similar, and the basics of batching and memory limits.
• Nice to have: LiveKit Agents, pipecat or WebRTC.
• German, or experience with German-language speech data.
• English proficiency is essential, both written and spoken, as it is the working language for all positions.

Responsibilities

• Improve turn-taking: voice activity and end-of-turn detection in live calls.
• Reduce end-to-end latency across STT, LLMs and TTS.
• Optimize prompting, tool calls, streaming and parallel requests in LLM usage.
• Serve our own speech models on GPUs and measure throughput.
• Fine-tune speech/language models for customer languages and voices.
• Build evaluation: test calls, benchmarks and quality metrics.

Skills

Python asyncio

Streaming pipelines

Speech (STT TTS VAD)

LLM APIs

GPU model serving

vLLM

Latency optimization

Tools

LiveKit

WebRTC

pipecat

Job description

Intro

For this position we are only looking for candidates located in Greece, Germany or Austria.

Nairon GmbH is a Swiss startup building AI voice agents that answer and make phone calls for businesses. Our platform runs real-time conversations over the phone and on the web, connected to our customers' telephony and business tools. We value clear communication, thoughtful engineering, and a collaborative approach to problem-solving. Join us as we continue to develop tools that make a difference.

Tasks

As a Voice AI Engineer at Nairon GmbH, you will make our agents sound fast, natural and reliable in live calls. Your responsibilities will include:

• Improving turn-taking: when the agent speaks, waits, yields or gets interrupted, including voice activity and end-of-turn detection.
• Cutting end-to-end latency across speech recognition, language models and speech synthesis, and making provider failover seamless.
• Optimising how we use LLMs in conversation: prompting, tool calls, streaming and speculative or parallel requests.
• Serving our own speech models (STT and TTS) on GPUs, measuring throughput and time to first audio.
• Fine-tuning speech and language models for our customers' languages and voices.
• Building evaluation: test calls, benchmarks and quality metrics that tell us when a change really helps.

Requirements

Experience:

A senior or strong mid-level engineer with production experience in real-time audio, conversational AI or ML model serving.

Technical Skills:

Required:

• Strong Python, including asyncio and streaming pipelines.
• Hands-on work with speech (STT, TTS, VAD) and LLM APIs in latency-sensitive systems.
• Model serving on GPUs, for example with vLLM or similar, and the basics of batching and memory limits.

Nice to have:

• LiveKit Agents, pipecat or WebRTC.
• Fine-tuning (LoRA or full) of speech or language models.
• Audio signal processing such as echo cancellation or noise suppression.
• German, or experience with German-language speech data.

Communication:

• English proficiency is essential, both written and spoken, as it is the working language for all positions.

Soft Skills:

• You measure before and after, and trust numbers over impressions.
• Ownership of a problem from the first bad call to the fix in production.

Benefits

• Flexible Work Setup: Work fully remotely or from a co-working space — whichever suits you best.
• Equipment Provided: Company laptop and phone provided for all employees.
• Collaborative Environment: Join a small, agile team where your contributions have a direct impact.
• Growth Opportunities: Work across the whole voice stack, from model serving to the conversation the caller hears.