Principal Software Engineer

***Must be living in Hungary*** Role Purpose The Principal Software Engineer serves as a technical expert and thought leader within the organization, driving the development of advanced software solutions and complex systems architecture. The purpose of this role is to lead the design and implementation of high-impact projects, guide technical decision-making, and influence the long-term strategy of the engineering organization. This role also involves providing mentorship and technical guidance to other engineers, contributing to the advancement of engineering standards, and ensuring the scalability, reliability, and performance of software systems. We seek a Principal Software Engineer with deep expertise in enterprise telephony, VoIP, and real-time media processing, plus hands-on experience designing cloud-native media services. This role spans two domains: Enterprise and PBX-based telephony systems (Cisco UCM, Skype for Business) A scalable cloud platform built around a new RTP Processor microservice for real-time media ingestion, processing, and distribution You will evolve architecture and ensure both native high-performance components and cloud services meet strict requirements for latency, reliability, scalability, and media fidelity. Act as a Subject matter expert, managing the full software development lifecycle including research, design, testing implementation and auditing. Lead design and system test case reviews, and usability or functional testing. Provide technical leadership to other developers. Make critical technical decisions that influence the direction of projects and the broader engineering organization. Lead and oversee the implementation of complex software projects, ensuring quality and timely delivery. Provide technical mentorship and thought leadership, helping to elevate the skills of the engineering team. Collaborate closely with product management and other stakeholders to align technical solutions with business needs. Architect real-time telephony and media processing systems. Design and maintain C++-based RTP and recording components for enterprise telephony. Design scalable, low-latency media microservices for real-time processing pipelines. Ensure interoperability between on-prem telephony systems and cloud services. Essential Expert C++ for real-time systems, Visual Studio 2026, WinAPI, advanced multithreading, Git/JIRA Media Processing: RTP transport, codec integration, file formats (e.g. WAV, MPEG-4, OGG), AGC/VOX detection, DSP-based quality analysis, multi-channel mixing VoIP Protocols: SIP, SCCP, SIPREC, RTP/RTCP, ICE/STUN/TURN, HTTP/WebSocket Security: RSA/DHE, AES, SRTP/SRTCP, secure media handling and key management Cloud Platform: RTP Processor microservice architecture, high throughput/low latency design, horizontal scalability Preferred - Networking & I/O: High-performance network programming, IOCP async I/O, OpenSSL/TLS Experience of one or more - Telephony Platforms: Experience with Cisco UCM, Avaya, Microsoft Teams, Skype for Business, IPC Unigy, or IPTrade