Principal Engineer

Responsibilities:

• A streaming, cascaded voice pipeline (ASR LLM TTS) with end-to-end response latency under ~800ms and a credible path toward the ~500-600ms range where callers stop noticing they're talking to AI.
• Turn-taking and barge-in that feel human - semantic endpointing, interruption handling, and full-duplex audio - not naive VAD silence timers.
• An evaluation and observability stack for voice: latency budgets per stage, transcription, hallucination and instruction-following evals, and replayable call traces.
• The orchestration layer: tool/function calling, RAG over customer knowledge, guardrails, and graceful fallback when a model or vendor degrades.

Requirements:

• Deep, hands-on experience building real-time or streaming systems - voice, video, RTC, audio, or low-latency ML serving. You understand where milliseconds go.
• Working knowledge of the modern agent stack: LLM orchestration, function/tool calling, streaming token pipelines, ASR/TTS, and how to evaluate non-deterministic systems.
• You've shipped something users talked to (or otherwise interacted with in real time) and made it fast and reliable.