AI Voice Engineer Needed (Vapi / Retell + Make.com + Twilio CRM Integration)

Voice AI Engineer (Vapi/Retell + Make.com/n8n + CRM Integrations) – Long-Term Technical Partnership About ArbiXcel ArbiXcel is an AI automation implementation partner helping heating, plumbing, HVAC and field service businesses improve customer response handling through AI-powered voice automation and CRM integrations. We work with businesses to identify operational bottlenecks, design automation solutions and manage implementation from technical planning through deployment. We are looking for an experienced independent Voice AI Engineer to become our long-term technical implementation partner for future client deployments and automation projects. This is not a one-off development task. We are looking to build a reliable working relationship with a skilled engineer who can take ownership of technical delivery while we manage client acquisition, discovery and account management. We are specifically looking for an independent freelancer who can work directly with our team. Preference will be given to individuals who personally handle the technical implementation rather than outsourcing delivery. Responsibilities You will be responsible for: • Reviewing technical requirements and recommending optimal architecture decisions. • Building and configuring conversational AI voice agents using Vapi.ai and/or Retell AI. • Designing automation workflows using Make.com or n8n. • Integrating voice systems with CRM and field service management platforms. • Configuring telephony systems, call routing, appointment capture, and escalation workflows. • Testing, troubleshooting and improving reliability of deployed systems. • Maintaining clear technical documentation and communication throughout projects. Required Technical Skills You should have strong experience with: • Vapi.ai and/or Retell AI voice agents • OpenAI or Anthropic API integrations • Deepgram, ElevenLabs, Cartesia, or similar voice technologies • Twilio telephony integrations • Make.com or n8n automation workflows • API integrations, webhooks, JSON payloads, and third-party SaaS platforms • Troubleshooting and optimising production automation systems Preferred Experience Experience with: • AI voice systems for customer service, lead qualification, scheduling, or dispatch workflows • CRM integrations such as Jobber, ServiceTitan, Commusoft, Housecall Pro, HubSpot, or similar platforms • UK/USA business workflows including postcode capture, appointment scheduling and customer support processes • Building low-latency conversational voice experiences Ownership & Delivery Requirements All workflows, prompts, automation scenarios, documentation and system configurations created for ArbiXcel projects must be built inside accounts controlled by ArbiXcel or the end client. Deliverables will remain the property of ArbiXcel and/or the client after agreed milestone payments are completed. Application Requirements To demonstrate attention to detail, begin your proposal with: ARBIXCEL Applications without this keyword will not be reviewed. Please include: A brief summary of your Voice AI experience. Examples of Vapi.ai, Retell AI, or similar voice systems you have personally built. A Loom video, portfolio link, live demo number, or demonstration of a working voice agent. Your preferred technology stack for building reliable AI voice automation systems. Your approximate weekly availability. Your estimated approach and timeline for building a production-ready voice automation system. We are looking for a skilled technical partner who values quality, reliability, and long-term collaboration. We look forward to reviewing your work.