Senior Software Engineer/Developer

Synergy Beam Solutions, providing IT solutions in various areas, specialized on creating turnkey solutions for customers in IT, Cybersecurity and other Business applications. As part of solutions our company developing the state-of-the-art telecommunication platform for call centers.

We're looking for a talented and motivated Senior VoIP Engineer to join our expanding team for build and maintain our Voip Saas system (voip clustering, webrtc, recordings, carriers and clients troubleshooting.

In this role, you'll design and build SIP-based systems focused on reliability, scalability, and security. You'll improve tooling, monitoring, and observability to ensure smooth, real-time call workflows at scale.

Join a mission-driven team tackling complex challenges and redefining how emergencies are managed worldwide. If you're ready to make a real impact, we'd love to hear from you.

Technical Requirements:

• At least 6+ years of software engineering experience with 4+ years of relevant experience with VoIP/SIP
• Experience developing VoIP, SIP, and Real Time Communication services
• Experience developing Linux-based solutions in Lua, Python, Go, or C/C++, with proficiency ideally in Lua and Python
• Understanding of network protocols, capture, and environments with technology like Wireshark, SIPp, libpcap, and Linux/BSD socket programming
• Strong Expirience in development with Freeswitch, Kamailio.
• Experience working with WebRTC, Turn/Turns servers
• Experience with AWS, Google Cloud, CloudFlare
• Experience with serial connected devices, GSM, E1 gateways.
• Experience scaling solutions with automated testing tools, frameworks and systems

Personal Requirements:

• English: B2 (Upper-Intermediate)
• Strong communication and interpersonal skills; is a team player with a positive attitude
• Expert troubleshooting skills and the ability to analyze problems and associated data structures.
• Highly self-motivated; ability to adapt and learn quickly in a fast-paced environment with a strong sense of ownership
• You are self-directed and enjoy solving difficult problems in a collaborative environment
• You are passionate about building and releasing software that serves a vital purpose

Will be a big plus if you will have:

• Experience in Lua, Python
• Experience working with embedded systems or hardware SIP devices
• Experience creating systems to test call flow scenarios and scalability using tools like SIP
• Understanding of software design principles with experience in RESTful APIs or RESTful web services
• Understanding the principles of routing in a global network and ways to optimize data delivery
• Understanding how AI driven features can be implemented and used in VoIP development and end products

Responsibilities:

• Advanced troubleshooting to diagnose complex call routing issues, codec mismatches, and SIP signaling problems, as well as analyzing packet captures (PCAPs), logs, and traces to identify root causes
• Maintaining and optimizing network and protocol performance, demonstrating deep expertise in SIP, RTP, TCP/IP, DNS, NAT traversal, firewall configurations
• Support integration and interoperability of PBX systems, soft switches, SBCs, and cloud platforms, ensuring smooth interaction between VoIP and other systems
• Monitoring quality metrics including MOS scores, jitter, and latency, responding to alerts from monitoring systems and proactively resolving performance degradation issues.
• Act as the final escalation point for unresolved L1/L2 issues, coordinating with carriers and vendors to address service-impacting incidents effectively.
• Lead architecture, development, and deployment of SIP and voice applications, including transcription, AMD/VMD, and AI integrations, while optimizing performance, scalability, and accessibility.
• Collaborate with Product, Engineering, and stakeholders to design solutions for critical challenges, apply best-in-class development practices to ensure ICC product reliability, and actively participate in code reviews and standups to share knowledge and improve team processes.
• Own meaningful parts of our platform have an impact, grow with the company.

Required skills experience

C#5 years

SIP5 years

VoIP5 years

Required domain experience

Telecom / Communications 5 years

Required languages

English C1 - Advanced

Job Type: Full-time

Pay: Up to 5,000.00грн per month