Senior AI Engineer - Voice

Responsibilities:

• Own the voice pipeline. Build and operate the real-time stack: telephony, streaming speech-to-text, LLM orchestration, text-to-speech, endpointing, barge-in, and the latency budget that keeps a conversation feeling human.
• Drive call quality relentlessly. Define what a good call is, measure it, and move the number. Build the evaluation harness: replayable audio and transcripts, regression suites, per-turn scoring so quality changes are provable rather than anecdotal.
• Handle the real world. Automated phone menus and DTMF, holds and transfers, voicemail, dropped calls and retries, noisy lines, accents, interruptions, and speaking clearly with an older audience.
• Scale calling volume reliably. Make the system hold up across thousands of calls a day, with clean handoffs to a human when the agent should stop.
• Close the loop with the people who hear every call. Turn what our team observes on real conversations into prompt, model, and pipeline changes, fast.
• Ship fast and iterate with real users. Deploy to production, listen to real conversations, and improve from them in days, not quarters.
• Lay the foundation for scale. Make architectural decisions in the voice stack that hold up from hundreds of calls a day to hundreds of thousands.

Requirements:

• You've built and shipped real-time voice AI to production not a demo, but a system that took real calls with real people.
• Hands-on depth across the voice stack: streaming speech-to-text, text-to-speech, turn detection and endpointing, barge-in, and latency optimisation under a real-time budget.
• Experience running telephony in production (SIP/PSTN, Twilio or similar) and the failure modes that come with it.
• You've built evaluation for voice or conversational systems.
• You've debugged AI systems in production and can trace a bad outcome through audio, transcript, and model behaviour to the actual cause.
• You're comfortable with ambiguity. The playbook doesn't exist yet, and you're excited to build it.

Nice to Have:

• Experience with real-time voice agent frameworks.
• Speech model fine-tuning, custom vocabularies, or domain adaptation for specialised terminology.
• Experience building agents that navigate automated phone systems on the other end of the line.
• Experience in healthcare or another regulated industry (HIPAA, PII/PHI handling, call recording and consent).