Full-Stack App Developer – AI & Voice Systems

We are an Australian technology start-up developing a new digital platform in the transport and mobility sector. We are looking for a talented part-time Full-Stack App Developer with strong AI development experience to join us as we prepare the platform for market launch.

The product is already well advanced and has a substantial working codebase and production infrastructure. This is not a greenfield project. You will work with an existing system, understand its architecture and help us complete, strengthen and expand the platform.

A major focus of the next development phase will be AI-powered voice functionality and intelligent agents, alongside continued development of our web, mobile and backend applications.

What You’ll Work On

Continue development of existing customer, driver and administration applications.
Build and integrate voice-command and conversational AI functionality.
Develop AI agents that can securely interact with application functions, APIs and backend services.
Work across frontend, backend, mobile applications and production infrastructure.
Integrate and maintain third-party APIs and services.
Debug, test and improve existing functionality.
Take features from concept through development, testing and production deployment.
Use modern AI development tools to accelerate development while maintaining high standards for security, reliability and code quality.

What We’re Looking For

Strong full-stack software development experience.
Strong TypeScript/JavaScript, React/Next.js and Node.js experience.
Mobile application development experience; React Native/Expo is highly desirable.
Experience with REST APIs, PostgreSQL/databases and cloud-hosted applications.
Genuine hands-on experience integrating LLMs and AI APIs into production applications.
Experience building AI agents, tool/function calling, automated workflows or conversational AI systems.
Experience with voice AI, speech-to-text, text-to-speech or real-time conversational systems is highly desirable.
Strong experience using AI development tools such as Claude Code, Codex, Cursor or equivalent.
Experience with platforms such as Stripe, Google Maps, Supabase, Twilio, Vercel or similar is advantageous.
Strong Git/GitHub and CI/CD experience.
Ability to understand and safely extend an existing production codebase rather than unnecessarily rebuilding working systems.
Strong attention to security, privacy, testing and production reliability.

Who We’re Looking For

We want someone who can take ownership, solve problems independently and communicate clearly. You should be comfortable working directly with the founder in a fast-moving start-up environment.

Importantly, we are looking for someone who understands how to use AI as an engineering accelerator, not as a replacement for sound software-engineering judgement.

The Opportunity

This is initially a part-time position with an early-stage Australian start-up approaching market launch.

For the right person, there is genuine potential for this position to develop into a long-term and potentially full-time role as the business grows.

You will be joining at an early stage, meaning the successful candidate will have the opportunity to make a meaningful contribution to the technology and future direction of the product.

When Applying

Please include examples of applications you have built or substantially contributed to, your experience with the technologies above, and at least one example of an AI agent or AI-powered application you have personally built.

If you have experience building voice or conversational AI systems, please provide details.

Please also include your GitHub/portfolio (if available), current weekly availability and preferred working