Senior Telephony Engineer

We are looking for a Senior Telephony Engineer to design, build, and operate enterprise-grade voice infrastructure — bridging traditional telephony with modern AI-powered real-time voice systems. You will work at the intersection of SIP/VoIP networking, cloud communications platforms, and AI voice agent development, enabling seamless caller experiences through intelligent automation. This role requires both deep protocol-level expertise and hands-on software development capability, with a strong emphasis on building production-ready SIP gateways and integrating real-time conversational AI services.

Key Responsibilities

SIP & Telephony Infrastructure

• Design, configure, and maintain SIP trunks, dial plans, and call routing across multi-platform environments.
• Build and operate SIP gateways — including custom media handling, audio transcoding (e.g., μ-law/G.711 to PCM16), and call state management.
• Configure and manage Session Border Controllers (SBCs) for enterprise-grade SIP peering, security, and interoperability.
• Implement SIP signaling stacks (e.g., pjsua2/pjproject or equivalent) for programmatic call handling and custom media port implementations.
• Ensure high availability, redundancy, and failover across voice infrastructure.
• Monitor and troubleshoot SIP signaling, RTP streams, and voice quality issues (jitter, packet loss, codec mismatches).

Cloud Voice & AI Integration

• Integrate telephony platforms with cloud-based real-time voice AI services (e.g., Azure Voice Live API, AWS Connect, or equivalent) via WebSocket-based media streaming.
• Build and maintain SIP-to-AI gateway architectures that bridge PSTN/SIP callers to speech-to-speech AI pipelines with low-latency audio delivery.
• Implement asynchronous, high-concurrency audio stream bridges to handle parallel voice sessions at scale.
• Integrate with Azure AI Foundry, Azure Communication Services (ACS), or equivalent platforms for PSTN, SIP transfer, IVR/DTMF routing, and number provisioning.
• Deploy and tune AI-powered voice bots and virtual agents, working with ASR, TTS, and end-of-turn detection configurations.
• Leverage cloud platform services (AWS or Azure) for infrastructure provisioning, container deployment, and voice workload scaling.

CTI & System Integrations

• Integrate voice platforms with enterprise systems (CRM, WFM, ticketing) via REST/SOAP APIs and webhook-driven event architectures.
• Implement Data Actions, OAuth 2.0 authentication, and secure API integrations across telephony and AI platforms.
• Collaborate with AI/ML teams on LLM-backed virtual agent design, function calling, and tool orchestration within voice flows.
• Configure inbound/outbound call flows, ACD queues, skills-based routing, and IVR self-service trees.

Development & DevOps

• Write production-grade code in Python, JavaScript, Java, or C# for SIP gateway logic, audio processing, and integration middleware.
• Work with SQL and database systems for call data storage, reporting, and analytics.
• Follow Git-based version control, CI/CD pipelines, and infrastructure-as-code (Terraform or equivalent) practices for deployments.
• Implement structured logging, observability, and alerting for real-time voice system health monitoring.

Governance & Documentation

• Produce detailed technical documentation: call flow designs, SIP ladder diagrams, integration runbooks, and API references.
• Enforce enterprise security standards including TLS for SIP signaling, SRTP for media, and network segmentation.
• Collaborate with network engineers to optimize QoS, bandwidth allocation, and voice traffic prioritization.