Sofware engineer

Polyworld Australia Pty. Ltd.; Sydney; On-site; AUD 140,000 - 190,000; Full time

Benefits offered by this job

Superannuation

Bondi Junction office

Job summary

Polyworld Australia Pty Ltd is seeking a senior engineer to own the full stack, from backend services and APIs to the web app and the React Native mobile app, plus the cloud infrastructure.

In a small team you will make architectural decisions, coordinate with software contractors, and base work on rigorous research and evaluation.

You will drive production reliability, monitoring, and performance work while shaping how the product is built and deployed at scale.

Qualifications

• At least five years of commercial software engineering experience.
• Strong backend depth including services, APIs, migrations.
• Web and mobile development experience with React Native/Expo preferred.
• AI-native working: design evaluations for non-deterministic outputs.
• Proficiency with CI/CD pipelines and infrastructure-as-code.
• Clear written English; decisions documented before building.

Responsibilities

• Build and operate backend services and APIs and data models beneath them.
• Develop the web app and the React Native/Expo mobile app, including releases to environments.
• Own deployment and infrastructure: CI/CD, infrastructure-as-code, and environments.
• Make the architecture decisions on service boundaries and client-backend interactions.
• Prototype retrieval and grounding approaches and build the evaluations that establish their effectiveness.
• Design and integrate a low-latency voice layer for mindcast in production.
• Keep production healthy through monitoring and performance work.

Skills

Backend engineering

APIs

Data modeling

Web development

React Native

Expo

CI/CD

IaC

Architecture

Research

Production monitoring

Education

Bachelor's degree in Computer Science or Software Engineering

Job description

You will be the senior engineer across the full stack: backend services, the web application, the React Native mobile application, and the cloud infrastructure beneath them. While a small company, you will coordinate and collaborate with software contractors; your role entails a broad scope, where you make architectural decisions rather than simply implementing them. Research is a genuine part of the role. The engineering practice for this kind of product is not yet settled - how to keep an answer tethered to its source material, how to measure whether a response is faithful to what the expert actually holds, and how to detect it when it is not. You will prototype approaches, run experiments against real expert material, and turn what works into systems that run reliably in production.

Key responsibilities

Build and operate backend services and APIs, and the data models beneath them

Develop the web application and the React Native and Expo mobile application, including releases to the Apple App Store and Google Play

Own deployment and infrastructure: CI/CD, infrastructure-as-code, and environments

Make the architecture decisions - where services divide, how the clients talk to the backend, and what can safely be deferred

Prototype retrieval and grounding approaches, and build the evaluations that establish whether they work

Design and integrate a low-latency voice layer that enables users to engage with a mindcast via natural speech, ensuring high-fidelity input and output in production

Keep production healthy through monitoring and performance work, and investigate when something breaks

Identify where the current architecture is limiting and propose the change

About you

A degree in computer science, software engineering or a related field

At least five years of commercial software engineering experience, across the full development lifecycle from requirements through to production support

Strong backend depth: services, APIs, relational data modelling, and migrations you have had to get right the first time

Web and mobile development experience. React Native and Expo preferred, though native or another cross-platform stack is equally relevant

AI-native working: you direct coding agents as a primary way of building, and you design evaluations for systems whose output is not deterministic

Experienced in CI/CD pipelines and infrastructure-as-code

Clear written English. Most decisions here are written down before they are built

About us

Polyworld Australia Pty Ltd builds mindcasts: a conversational form of an expert's work, in which every answer traces back to what that expert has actually said, written and argued. It is not a general-purpose chatbot. It is one named person's knowledge and reasoning, available to be questioned directly, at any hour and from anywhere.

Conveniently located office in Bondi Junction. On the Eastern Suburbs line and the bus interchange, a short walk from the beach, and not a CBD commute

Full technical ownership and direct founder collaboration: you own the architecture and product decisions with no inherited roadmaps or top-down mandates

Research as a real part of the job rather than a side project. The grounding and evaluation problems are genuinely unsolved, and working them out is the work

Superannuation paid in addition to the salary