Member of Technical Staff, Cekura (San Francisco, In-Person)

Cekura is building a voice AI engineering platform for testing, monitoring, and continuously improving voice agents. The Member of Technical Staff will build simulation engines, LLM-powered evaluation and self-improvement systems, audio and speech analysis capabilities, real-time voice infrastructure, observability pipelines, and end-to-end product features.

Responsibilities:

• Build the testing and simulation engine. Design and ship systems that simulate thousands of realistic conversations against customer agents across voice, chat, and phone, with control over personas, interruptions, background noise, and edge cases
• Push the frontier of agent evaluation. Build LLM-powered evaluators, metrics, and the closed self-improvement loop at the heart of the product: detect failure, reproduce in simulation, generate the fix, test it thoroughly, and raise the PR, all autonomously. This includes adversarial red-teaming for jailbreaks, PII leaks, and off-script behavior, plus production monitoring with live drift detection
• Do applied audio and speech research. Go beyond the transcript. Separate background noise from actual speech, and map the paralinguistic layer of conversation (emotion, tone, silences, hesitations, speaking rate, overlaps) into structured signals, so agents are evaluated on how something was said, not just what
• Own real-time voice infrastructure. SIP, WebRTC, WebSockets, STT/TTS pipelines, and providers like Twilio, Vapi, Retell, LiveKit, and Pipecat. Latency, barge-in, and audio quality are first-class problems here
• Ship end-to-end. Take features from design to production. You own the full stack of what you build: backend, infra, evals, and the product surface customers touch
• Shape how we build. We're a small, senior team. Your architectural decisions, code standards, and technical taste will compound as the team grows