Lead Voice Infrastructure Engineer

Stuut•San Francisco, CA

10d

About The Position

Stuut is transforming accounts receivable for B2B companies—making collections smarter and faster for companies that have historically relied on manual processes that are labor intensive and costly. Our platform is gaining traction with finance teams across industrials, chemicals, and manufacturing sectors from Fortune 10 brands to scaling midmarkets. We're backed by top-tier investors including a16z, Khosla, Activant, 1984 Ventures and Page One. The Role Voice Telecommunication is a critical channel for accounts receivable. Customers pick up the phone. Agents need to call. Transfers need to work. Voicemails need to land. We are building AI agents that do real work across collections, cash application, disputes, customer communications and the phone is where much of that work happens. We're hiring a Senior Telephony Engineer to build the foundation for AI-driven voice at Stuut. You'll work closely with our engineering, product, and go-to-market teams to design and operate the telephony infrastructure that powers production phone interactions at scale. This role sits at the intersection of telephony infrastructure, realtime voice systems, AI voice agents, and finance workflows. We are looking for someone who has real depth in telephony, can build distributed systems that hold up under production pressure, and understands that infrastructure decisions shape product outcomes. You will own the systems that determine whether calls connect, transfers complete, and business results get measured. This is the first dedicated voice infrastructure hire at Stuut. You will define how we build this.

Requirements

Are a strong senior software engineer with experience building distributed backend systems
Have meaningful experience with telephony systems: SIP, RTP, PSTN connectivity, trunks, number provisioning, or call routing
Are comfortable working on realtime media systems where latency, reliability, and observability matter
Can 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
Are pragmatic, hands-on, and able to move between architecture and direct execution

Nice To Haves

Have experience with WebRTC, realtime media platforms, or speech systems (streaming STT, TTS, turn detection, conversational voice agents)
Have worked with contact center workflows, IVR systems, or enterprise telephony integrations
Have experience with Go, Python, C, or C++
Are excited about building the infrastructure that will define AI-powered business communication over the next decade

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