Software WebRTC Engineer

Software WebRTC Engineer (EU, Remote) at Telness Tech Telness Tech is on a mission to simplify and digitize the telecom industry. Our platform powers next‑generation mobile providers, from traditional MVNOs to eSIM challengers and non‑telecom players looking to embed connectivity into their offerings. With our roots in Stockholm and our sights on a global scale, we’re building the future of telecom—fast, flexible, and customer‑first. Your Mission As a WebRTC & Real‑Time Communications Engineer, you’ll be the in‑house expert for everything related to how voice flows 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 ensure 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. 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. What You’ll Do Define and own the company‑wide WebRTC and real‑time communication architecture. Integrate and optimize SIP/RTC systems and signaling flows with existing backend services, media handling, APIs, interoperability and third‑party platforms. Contribute to the evolution of the company’s real‑time communication stack, keeping up to date with emerging standards (e.g., WebRTC, AI‑analytics, AI‑agents). Ensure compliance with SIP/VoIP standards and interoperability with various real‑time communications devices, softphones, and platforms. Write and maintain high‑quality, production‑grade code in real‑time communications‑related components. Own the development and evolution of user‑facing real‑time communication interfaces, including white‑labelled mobile apps, desktop softphones, and web‑based configuration portal. Troubleshoot and resolve complex communications‑related issues across signaling, media, and infrastructure layers. Establish and document best practices, coding standards, and guidelines for RTC development. Work with DevOps and infrastructure engineers to ensure communications services are highly available, monitored, and resilient under load. Collaborate closely with cross‑functional teams (backend, frontend, infrastructure, and product) to deliver real‑time communications features and services. Mentor engineers working with real‑time communications and promote knowledge sharing across the organization. What You Bring To The Table 5+ years of experience in SIP/VoIP/RTC development, preferably in telecom, UCaaS, or real‑time communication systems. Experience working with SBCs, SIP servers (e.g., Kamailio, OpenSIPS, FreeSWITCH, Asterisk), and media servers. Experience troubleshooting SIP signaling, RTP/RTCP, NAT traversal, and related real‑time communication challenges. Working in a fast‑paced startup/scaleup. Deep understanding of SIP, SDP, RTP/RTCP, WebRTC and related VoIP protocols. Development experience in relevant languages (e.g., Go, C/C++ or similar). Strong development experience with concurrency and high‑availability. Familiarity with SIP debuggers, protocol analyzers (e.g., Wireshark), and performance testing tools (e.g., SIPp). Experience in Typescript, React, and GraphQL for the Frontend (or similar). Experience with cloud platforms, preferably AWS. Experience working with Kubernetes. Why Telness Tech? We’re building for how telecom should be: fast‑moving, easy to use, and built for the people who use it. At Telness Tech, you’ll join a curious, ambitious, and transparent team. We work hard, we move fast, and we support each other every step of the way. Benefits A product that’s already shaking up the telco space. A hybrid (or fully remote) setup based in Europe (HQ in central Stockholm). A growing company backed by strong investors. The chance to shape Telness Tech’s commercial future, globally. A tight‑knit, no‑ego culture where ideas matter more than titles. Real ownership and the support to make bold things happen. Additional Information Seniority level: Mid‑Senior level Employment type: Full‑time Job function: Engineering and Information Technology Industries: Telecommunications Referrals increase your chances of interviewing at Telness Tech by 2x. Sounds like your challenge? Let’s talk. #J-18808-Ljbffr