WebRTC Engineer
Telness Tech is rethinking how telecom should work in the digital era.
Born in Sweden and expanding across USA and Europe, their SaaS platform, Seamless OS, enables telecom and non-telecom businesses to launch and run telecom and communication services with speed and simplicity.
To take this vision further, they’re looking for a WebRTC Engineer — someone ready to own the real-time communication layer of their products, being an integral part of backend services and frontend teams to ensure world-class performance, scalability, and reliability.
¿Qué harás?
At Telness Tech, they’re building the technology that lets new and digital telecom brands come to life and succeed — fast, scalable, and entirely in the cloud. Their platform powers both their own operator and dozens of customers across Europe and the US who want to deliver modern, digital-first communication services.
Now they’re looking for someone ready to own one of the most complex and impactful parts of that system: real-time communication.
As a WebRTC & Real-Time Communications Engineer, you’ll be the in-house expert for everything related to how voice flow through Telness Tech’s platform. You’ll design and evolve the architecture that connects SIP, media servers, and backend APIs, making sure every call, every signal, and every packet travels reliably and efficiently.
You’ll work hands-on with technologies like Go, WebRTC, SIP, RTP/RTCP, and Kubernetes, building and optimizing the systems that make real-time communication scalable and resilient. From media handling to signaling flows, from debugging protocol-level issues to shaping new features, you’ll make sure communication just works.
This isn’t a pure backend role — you’ll also collaborate with customers and frontend engineers, who build Telness Tech’s softphones and apps (React Native, Electron), ensuring seamless integration between backend, APIs, and clients. You’ll help define best practices for RTC development, and bring clarity and structure to how the company approaches voice and video services across products.
You’ll work closely with Hantao (Engineering Manager), and other senior engineers to design for scale, reliability, and quality — and you’ll have a real say in technical decisions that shape the platform’s evolution.
In short: you’ll take ownership of the technology that keeps Telness Tech’s products connected in real time. A hands-on, high-impact role where every line of code has a direct effect on how thousands of users experience voice and video every single day.
Tu evolución
En 1 mes
You’ll be settling into the team and getting to know how Telness Tech builds and operates its platform. You’ll meet Jonas (CTO), the Engineering Lead, and the engineers working across backend, infrastructure, and product, and start digging into the PBX and communication stack.
During this first month, you’ll review the current WebRTC and SIP architecture, get hands-on with the media handler recently built by your predecessor, and start to understand how signaling and media flow through the system.
It’ll also be a time to ask questions, give feedback, and share ideas — they’ll value your fresh perspective from day one.
Tus responsabilidades
Own the real-time communication stack - Take full ownership of how voice and video flow across Telness Tech’s products — from signaling and media routing to APIs and integrations. You’ll evolve the WebRTC and SIP architecture to keep it scalable, reliable, and ready for the next stage of growth.
Design and build the core of real-time communication - Develop, optimize, and maintain components that handle everything from call setup and media quality to interoperability with external systems and devices.
Work hand in hand with the Engineering Manager
Solve complex problems at every layer - Dive deep into signaling flows, troubleshoot tricky RTP or NAT traversal issues, and ensure performance and resilience across all environments.
Raise the technical bar - Share your knowledge, guide teammates, and help define best practices around code quality, observability, and system scalability. You’ll set the standard for how Telness Tech builds and maintains real-time systems.
¿Cómo lo harás?
You’ll join a small, talented, and highly autonomous engineering team led by Engineering Manager 🤝. They work in an open, collaborative environment where everyone takes real ownership of what they build.
The development culture is pragmatic and engineering-driven: code is reviewed carefully, systems are monitored closely, and decisions are made based on data and impact — not hierarchy.
You’ll work fully remotely, syncing daily with your teammates across Europe. Communication flows naturally through stand-ups, async updates, and short feedback loops. You’ll have the freedom to suggest improvements, experiment, and make technical decisions that matter.
And you won’t be on your own: while you’ll own the RTC domain, you’ll have the support of backend, frontend, and infrastructure engineers to help bring your ideas to life. The goal is to keep building fast, with quality and simplicity at the core.
¿Cuándo trabajarás?
At Telness Tech, collaboration and communication are key — that’s why everyone works during the same core hours to stay connected and aligned. The regular schedule is Monday to Friday, from 8:00 to 17:00 CET, including a one-hour lunch break.
There is some flexibility: employees can start and finish up to an hour earlier or later (for example, 7:00–16:00 or 9:00–18:00 CET), as long as they are available during the main part of the day. No one should start later than 9:00, ensuring smooth teamwork and communication across the company.
Día laborable
Jornada completa
Vacaciones
30 días¿Dónde trabajarás?
Remoto
Telness Tech is a remote-friendly company with its headquarters in Stockholm 🇸🇪, offices in London and New York 🌎, and a growing presence in Spain 🇪🇸.
You’ll work remotely from Spain, collaborating daily with teammates based across Europe. That said, Telness Tech is currently building a new Tech Hub in Madrid, and over the next few months more engineers will be joining there — so their preference would be for someone based in, or open to being regularly connected with, Madrid.
They understand how niche this profile is, so the priority is finding the right person, wherever they are. But ideally, they’d love you to become part of that new hub and help shape it from the ground up.
You’ll also have the chance to visit the Stockholm HQ occasionally (around once per quarter) for team meetups, planning sessions, or simply to grab a fika ☕ with your colleagues in person.
¿Con quién trabajarás?
The Engineering team at Telness Tech is around 20 people today — a well-balanced, experienced and collaborative group building the platform that powers digital telecom services across Europe.
New talent will join in the coming months, but here are some of the people you’ll be working closely with:
- Jonas Cedenwing (CTO & Co-founder) – A hands-on technical leader and one of the minds behind Telness Tech’s architecture. Jonas has spent years blending telecom expertise with a modern, product-focused mindset. He’s deeply involved in engineering decisions and always open to new ideas that make the platform faster, simpler, and more reliable.
- Hantao Wang (Engineering manager) - Engineering Manager at Telness Tech, he leads the development team and drives the technical roadmap on core products.
- Martin Wohlfart (Principal Engineer) - A Principal Engineer at Telness Tech, he contributes across the entire stack, bringing deep knowledge of both frontend and backend systems.
Around them, you’ll find a talented group of backend, frontend, infrastructure, and product engineers — passionate about building clean, resilient systems that enable seamless communication for Telness Tech’s partners and users.
¿Qué piden?
They’re looking for someone with solid experience building real-time communication systems — ideally with a background in WebRTC, SIP, and VoIP.
You should feel comfortable designing and debugging signaling and media flows, writing production-grade code in Go (or similar), and working across modern cloud environments (AWS, Kubernetes).
If you understand how WebRTC clients integrate on the frontend (React Native, Electron) — even better.
Most importantly, they value curiosity, ownership, and collaboration. You’ll be their in-house expert in RTC, but also a teammate who enjoys solving complex problems together.
Tecnologías
Innegociable
WebRTC
Avanzado 
SIP
Avanzado 
Go
Intermedio
Estaría bien
Asterisk
Intermedio 
Kubernetes
Intermedio 
PostgreSQL
Básico
Suma puntos
React
Básico 
REST
Básico
Otras habilidades
Innegociable
Tolerancia a la incertidumbre
Adaptabilidad al cambio
Atención al detalle
Capacidad de dar feedback
Visión estratégica
Trabajo en equipo
Idiomas
¿Qué ofrecen?
Salario
Hasta €70KRemoto
100%At Telness Tech, you’ll join a company that truly lives by what it builds — a place where technology, trust, and people go hand in hand.
They offer:
- 💰 A salary of up to €70 000/year, depending on your experience and what you bring to the team.
- 🏡 Full remote work from anywhere in Spain, with flexible hours and full autonomy to organize your day.
- 🌴 30 days of paid vacation per year — because balance matters.
- 💡 Equity options (Optional) — you’ll share in the success you help create.
- 🚀 Learning and growth opportunities — you’ll have time and budget for courses, conferences, or anything that helps you stay ahead in RTC and beyond.
Beneficios
Presupuesto para formación
Presupuesto para Conferencias
Dinámicas y eventos de teambuilding
Vacaciones Extra
What the FAQ?
EU residents only, due to administrative reasons.
The process is simple and transparent. You’ll first have a chat with Jonas (CTO) and Simon (Engineering Manager) to get to know each other and talk about your experience.After that, there’ll be a technical interview or small practical test to go deeper into your skills and approach to problem-solving.Finally, you’ll meet someone from the leadership team for a cultural fit conversation.
They move fast — the whole process usually takes a few weeks from first chat to offer. 🚀