Sofware engineer

Polyworld; Sydney; On-site; AUD 180,000 - 240,000; Full time

Benefits offered by this job

Superannuation

Job summary

Polyworld Australia Pty Ltd seeks a senior engineer to own the full stack—from backend services to the web app, the React Native mobile app, and its cloud infrastructure. In a small company, you will shape architecture, collaborate with contractors, and drive research and experiments to turn proven approaches into production systems.

You will prototype retrieval and grounding approaches, design a low-latency voice layer for mindcast interactions, and ensure production health through monitoring

Qualifications

• Degree in computer science, software engineering, or a related field.
• Minimum five years of commercial software development experience across the full lifecycle.
• Strong backend depth with APIs, relational data modelling, and migrations.
• Web and mobile development experience; React Native and Expo preferred.
• AI-native coding and evaluating non-deterministic system outputs.
• Familiarity with CI/CD pipelines and infrastructure-as-code.
• Excellent written English for documentation and design decisions.

Responsibilities

• Build and operate backend services and APIs with underlying data models.
• Develop web app and React Native/Expo mobile app including store releases.
• Own deployment and infrastructure with CI/CD and IaC.
• Make architecture decisions on service boundaries and client-backend communication.
• Prototype retrieval and grounding approaches and build evaluations.
• Design and integrate a low-latency voice layer for mindcast interactions.
• Maintain production health through monitoring and performance work.
• Identify bottlenecks and propose architectural changes.

Skills

CS degree

5+ yrs exp

Backend depth

React Native

Expo experience

CI/CD pipelines

IaC

English writing

AI-native work

Education

Degree in CS/SE

Tools

React Native

Expo

CI/CD tooling

Terraform

Cloud infra

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