Realtime Backend Engineer (LiveKit / SIP)

For this position we are only looking for candidates located in Greece.

Nairon 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 Realtime Backend Engineer at NAIRON, you will build the services that carry every call and every event through our platform. Your responsibilities will include:

• Designing, building and running microservices around our LiveKit-based real-time media platform.
• Working with messaging and realtime data systems such as NATS, Kafka and Redis-compatible stores.
• Connecting phone calls to the platform: SIP trunks, routing, transfers and call quality, together with the team.
• Building integrations with our customers' systems, such as CRMs, calendars and ticketing tools.
• Running services in the cloud with Docker and Kubernetes, with metrics, logs and traces you can trust.
• Taking part in code reviews, technical discussions and architectural planning.

Requirements

Experience:

A mid-level to senior backend engineer with experience running distributed, real-time systems in production.

Technical Skills:

Required:

• Strong Python (asyncio, FastAPI or similar); TypeScript or Go is a plus.
• Microservice design: messaging, idempotency, backpressure and failure handling.
• Experience with NATS, Kafka or a comparable realtime messaging or database system.

Nice to have:

• LiveKit, WebRTC or other real-time media.
• SIP and VoIP: trunks, Kamailio or similar proxies, RTP troubleshooting.
• Cloud experience (AWS or similar), Kubernetes and observability with OpenTelemetry and Grafana.

Communication:

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

Soft Skills:

• Calm, systematic debugging when something breaks under load.
• Ability to work independently in a distributed team and to write things down.

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: See the whole path of a call, from the phone network to the AI agent, and grow into telephony or AI work.

If you enjoy building systems that have to work in real time, we'd love to hear from you.