Lead Telephony Engineer

Stuut is transforming accounts receivable for B2B companies, making collections smarter and faster. They are seeking a Senior Telephony Engineer to build the foundation for AI-driven voice, working closely with various teams to design and operate telephony infrastructure that supports production phone interactions at scale.

Responsibilities:

• Design, build, and operate telephony services that manage phone numbers, SIP trunks, carrier integrations, and call routing at scale
• Develop reliable signaling and media systems that bridge traditional telephony with realtime voice infrastructure and AI pipelines
• Build and improve core voice workflows: outbound calling, inbound routing, warm transfer, voicemail handling, DTMF interaction, and human handoff
• Work closely with speech and AI systems across STT, TTS, turn-taking, interruption handling, and agent orchestration
• Improve call quality, latency, reliability, and debuggability across the voice stack
• Build internal APIs and platform primitives that make voice capabilities accessible to product and engineering teams
• Instrument voice workflows so we can measure business outcomes: answer rates, transfer success, voicemail outcomes, and resolution rates
• Work with carriers and external vendors to expand coverage, improve routing performance, and handle regulatory or operational requirements
• Dive into production issues when needed, including packet captures, signaling traces, vendor debugging, and incident response

Requirements:

• Strong senior software engineer with experience building distributed backend systems
• Meaningful experience with telephony systems: SIP, RTP, PSTN connectivity, trunks, number provisioning, or call routing
• Comfortable working on realtime media systems where latency, reliability, and observability matter
• Ability to debug across layers, from APIs and backend services down to protocols, signaling flows, and packet-level issues
• Think beyond code and understand how infrastructure decisions affect product behavior, developer experience, and end-user trust
• Pragmatic, hands-on, and able to move between architecture and direct execution
• Experience with WebRTC, realtime media platforms, or speech systems (streaming STT, TTS, turn detection, conversational voice agents)
• Worked with contact center workflows, IVR systems, or enterprise telephony integrations
• Experience with Go, Python, C, or C++
• Excited about building the infrastructure that will define AI-powered business communication over the next decade