Mid-Level Voice AI Developer – Retell AI / Python / AWS

Location: Dallas, TX – North Dallas
Work Arrangement:  On-Site
Experience Level: Mid-Level
Experience Required: 5–8 years

Job Summary

We are seeking a hands-on Mid-Level Voice AI Developer to join our team in North Dallas, TX. This is an on-site position for an experienced software engineer who has a strong track record of building and deploying production-grade conversational voice AI systems.

The ideal candidate will have deep, hands-on production experience with Retell AI and will be responsible for the technical execution of our voice automation platform. You will build and optimize sophisticated inbound and outbound voice agents supporting sales, appointment scheduling, and customer service workflows.

This role combines voice AI, LLMs, real-time communications, APIs, telephony, cloud services, and backend engineering. You will work closely with business and technical stakeholders to design reliable voice agents capable of handling real-world conversations, interruptions, scheduling, customer requests, objections, and complex edge cases.

Important: Proven production experience with Retell AI is a strict requirement for this position. Candidates without hands-on Retell AI experience will not be considered.

Key Responsibilities

Retell AI & Voice Agent Development

• Design, build, test, and deploy production-grade inbound and outbound voice agents using Retell AI.
• Work extensively with the Retell AI platform, SDKs, APIs, and custom LLM WebSocket integrations.
• Customize and extend Retell AI configurations beyond standard/default capabilities.
• Develop voice agents for sales, appointment scheduling, lead qualification, customer service, and support.
• Build robust conversational flows capable of handling interruptions, objections, clarifications, and unexpected customer responses.

Sales & Scheduling Automation

• Integrate voice agents with scheduling platforms such as Cal.com, Calendly, custom scheduling systems, CRMs, and internal applications.
• Enable agents to retrieve real-time availability, schedule appointments, reschedule appointments, and process cancellations during live calls.
• Develop outbound calling workflows designed to support lead engagement, qualification, appointment setting, and other growth initiatives.
• Integrate voice workflows with existing business systems and operational processes.

Real-Time Performance & Latency

• Optimize voice AI systems for low-latency, natural conversations.
• Minimize dead air and response delays in real-time voice interactions.
• Implement effective handling of human interruptions and conversational turn-taking.
• Troubleshoot latency and performance issues across LLM, WebSocket, API, telephony, and backend components.
• Monitor and improve reliability and responsiveness as call volume increases.

Backend, APIs & Data Integration

• Develop backend services and integrations using Python and AWS Lambda.
• Build and maintain RESTful APIs, webhooks, asynchronous workflows, and real-time data integrations.
• Synchronize call outcomes, customer information, appointment data, notes, and other events with internal databases and CRM systems.
• Design reliable event-driven workflows for real-time voice interactions.
• Work with databases and cloud services to support scalable voice automation infrastructure.

Prompt & Conversation Engineering

• Develop structured prompts and conversational logic for production voice agents.
• Design state machines and decision logic that allow agents to maintain context throughout conversations.
• Implement guardrails for business rules, compliance requirements, customer service scenarios, and sales workflows.
• Test and refine prompts to improve accuracy, reliability, conversion, and customer experience.
• Identify and resolve edge cases across complex conversational scenarios.

Analytics & Quality Monitoring

• Analyze Retell AI call logs, transcripts, and audio recordings.
• Monitor KPIs such as call resolution, appointment-booking conversion, call completion, latency, and agent performance.
• Identify recurring conversation failures and implement technical improvements.
• Build or maintain monitoring and reporting processes for voice AI quality and reliability.

Required Qualifications

• 5–8 years of software engineering experience, with strong hands-on experience developing production software systems.
• Deep, hands-on production experience with Retell AI — STRICT REQUIREMENT.
• Demonstrated experience building and deploying production-level voice AI agents.
• Strong proficiency in Python.
• Advanced experience with AWS Lambda and other AWS services.
• Strong understanding of asynchronous programming and real-time streaming data.
• Experience working with databases and backend systems.
• Extensive experience developing and integrating REST APIs and webhooks.
• Experience with telephony platforms such as Twilio and/or Vonage, including phone numbers, call routing, outbound calling, and call triggers.
• Experience designing conversational logic, state machines, prompts, and LLM-powered workflows.
• Ability to troubleshoot complex real-time systems involving APIs, WebSockets, LLMs, telephony, and backend services.
• Strong understanding of software development, debugging, testing, and production deployment practices.
• Must be able to work full-time on-site in North Dallas, TX.

Preferred Qualifications

• Local to the Dallas-Fort Worth metroplex.
• Experience working with high-volume outbound AI calling systems or dialers.
• Experience optimizing outbound sales and appointment-setting voice agents.
• Experience implementing security controls and guardrails for sensitive customer information.
• Experience integrating AI agents with CRMs, scheduling platforms, and custom business applications.
• Experience with advanced Retell AI customization and custom LLM/WebSocket architectures.
• Familiarity with regional telephony routing and communications infrastructure.
• Experience monitoring and optimizing voice AI systems at scale.

What You'll Work On

You will work on real-world voice AI systems that interact with customers over the phone and are expected to perform reliably in production. Your work will directly impact:

• Inbound customer service automation
• Outbound sales and lead engagement
• Appointment scheduling and calendar management
• Customer qualification
• CRM and database synchronization
• Voice AI performance and latency
• Call quality and conversational reliability
• High-volume automated calling workflows

Ideal Candidate

The ideal candidate is a hands-on engineer rather than a purely theoretical AI/ML professional. You should be comfortable getting deep into the implementation details of a production voice AI system — from Retell AI agent configuration and prompt engineering to Python backends, WebSockets, AWS Lambda, APIs, databases, and telephony integrations.

You should enjoy solving problems involving real-time systems, conversational AI, latency, integrations, and production reliability, and be comfortable taking ownership of features from architecture through deployment and optimization.