Senior Telephony Engineer

Senior Telephony Engineer

Location: Bristol In House/Hybrid (must be within commutable distance of Bristol)

Employment Type: Full-time

Experience Level: Senior

Salary: £80k - £100k

About the Role

We are seeking an experienced Senior Telephony Engineer to design, build, and scale a robust, cloud-based voice communications platform. This role will focus on developing the core telephony infrastructure that powers programmable voice, call routing, real-time audio processing, and system reliability at scale.

You will play a key role in shaping the architecture of a modern communications platform and will work closely with backend, DevOps, and AI teams to deliver high-quality, production-grade voice services.

What You'll Do

• Architect and implement a scalable telephony infrastructure supporting inbound and outbound voice calls.
• Design call routing, session management, and failover strategies for high availability.
• Build and maintain real-time voice services using SIP, RTP, and WebRTC technologies.
• Develop APIs and internal tooling for call control, provisioning, and monitoring.
• Ensure low-latency, high-quality audio and reliable call delivery across regions.
• Collaborate with AI teams to integrate voice services with speech recognition, TTS, and conversational agents.
• Lead troubleshooting and optimization of complex telephony and networking issues.
• Define best practices for security, compliance, and observability within voice systems.

What We're Looking For

• 5+ years experience working with telephony or real-time communications systems.
• Strong knowledge of SIP, RTP, VoIP, and call signaling protocols.
• Experience building or operating large-scale voice or communications platforms.
• Proficiency in at least one backend language (e.g., Python, Go, Java, or C++).
• Strong understanding of networking concepts (NAT traversal, codecs, latency, jitter).
• Experience with cloud infrastructure and distributed systems.
• Ability to lead technical decisions and collaborate across multiple engineering disciplines.

Nice to Have

• Experience with WebRTC media servers or SIP application servers.
• Familiarity with telecom regulations, number provisioning, and compliance requirements.
• Experience with monitoring real-time systems and call-quality metrics.
• Exposure to AI voice pipelines (ASR, TTS, real-time streaming).

Why Join Us

• Opportunity to build a foundational communications platform from the ground up.
• Work on complex, real-time systems at scale.
• Influence architecture and long-term technical direction.
• Flexible working arrangements and competitive compensation.
• Collaborative team environment with a strong engineering focus.