Retell AI Voice Prompt Engineer

Senior Voice AI Engineer — Retell AI (Part-Time, Remote) 📍 Remote (US-based) | ⏱ Part-time | 🖥 Contractor or Part-time Employee

About Aura 300 Aura 300 is an AI-native revenue platform built for the global salon industry. Our AI voice agents handle front desk automation, missed call recovery, client retention, and new client acquisition for salons across Australia, the US, and the UK. 50+ salons, growing fast, and expanding into the US.

We're a small, high-conviction founding team that moves quickly and builds things that actually work in the real world — not just in demos.

The Role We're looking for a Senior Voice AI Engineer who is as comfortable architecting elegant prompt systems as they are shipping production-ready voice agents. You'll own the technical quality of our AI voice agents.

This is a hands-on role. You'll be setting the standard, reviewing work, and shipping alongside your team — not just directing from a distance.

What You'll Own

* Architecture and optimisation of voice agent prompt systems in Retell AI

* Performance tuning — latency, conversation flow, fallback handling, accent robustness

* Integration with salon CRM and booking platforms (Timely, Fresha, Shortcuts, Phorest)

* Managing and mentoring one junior prompt engineer

* Defining prompt engineering standards, testing frameworks, and documentation

* Collaborating directly with the founders on new agent features and market expansion (AU → US → UK)

What You'll Bring

* 3+ years in prompt engineering or conversational AI, with at least 1+ year specifically in voice AI

* Hands-on production experience with Retell AI — this is non-negotiable

* Strong working knowledge of ElevenLabs and Twilio

* Deep understanding of multi-turn conversation design, interruption handling, and real-world telephony constraints

* Experience integrating voice agents with third-party APIs and CRMs

* A portfolio or examples of live voice agents you've built and deployed — we'll ask to hear them

* Comfortable in a fast-moving startup environment where you ship, iterate, and own outcomes

Nice to Have

* Experience in the salon, hospitality, or service business vertical

* Familiarity with Vapi or Bland AI

* Prior experience managing or mentoring junior engineers

Why Join Aura

* Work on a genuinely novel product — AI voice agents handling real salon calls, real bookings, real revenue

* Direct access to founders — no layers, no bureaucracy

* Equity available for the right candidate

* Part of a global expansion with immediate impact across AU, US, and UK

* To Apply Send a short note on your Retell AI experience + a link or demo of a voice agent you've built. Applications without evidence of Retell AI experience will not be reviewed.