A leading R&D; company based in Castle Hill are currently seeking a full-stack developer to join their growing engineering team.

You’ll be working within a technically strong R&D; environment, developing and supporting software used across the company’s products and systems.

The role will involve a mix of front-end and back-end development, working closely with a small team of fullstack devs and AI developers to build reliable, user-friendly applications.

The company are looking for an engineer that's interested in real-world technology and product development, rather than purely web-based projects.

This is a full-time, permanent position which requires you to be onsite in the Castle Hill office.

You must have working rights in Australia to be eligible for this position.

Key Requirements:

Backend Development:

API Development & Architecture

- Design, implement, and maintain RESTful APIs using NestJS, with full OpenAPI/Swagger documentation.
- Implement secure JWT-based authentication with access/refresh tokens using HTTP-only cookies.
- Define and validate DTOs with NestJS validation pipes for type-secure request/response contracts.
- Configure CORS policies, rate limiting (e.g., 40 requests/min/user), and comprehensive request logging.
- Maintain backward-compatible API versioning, planning for future iterations.

Asynchronous Processing & Job Queues

- Architect and maintain BullMQ queues for background job processing.
- Handle long-running tasks (e.g., floor plan analysis, ML API integration) with retry and exponential backoff strategies.
- Monitor queue health, optimise concurrency, and scale processing capacity efficiently.

Database Design & Optimisation

- Design normalised PostgreSQL schemas with proper relationships, constraints, and indexing.
- Use TypeORM for entities, migrations, and data integrity management.




- Optimise queries to prevent N+1 issues and ensure sub-second response times.
- Implement transactional consistency for critical multi-step operations.
- Work with Google Cloud SQL for high availability, backups, and disaster recovery.

Cloud & Infrastructure Integration

- Integrate with Google Cloud Storage for secure file handling.
- Manage Redis connections for BullMQ job persistence.
- Design event-driven systems using Google Cloud Pub/Sub; implement publish-subscribe patterns, versioned message schemas, and dead-letter handling.
- Ensure reliable message delivery (exactly-once / at-least-once semantics) and monitor system metrics.
- Deploy containerised microservices on Google Cloud Run with auto-scaling, health checks, and zero-downtime updates.
- Build serverless functions (GCF Gen 2) triggered by HTTP, Pub/Sub, Firestore, or Storage events with proper retry, idempotency, and performance optimisation.

Highly Desirable Skills:

- Build responsive, TypeScript-based React.js applications.
- Good knowledge using Javascript
- Develop reusable UI components, manage state (Redux, Zustand, or Context API), and integrate backend APIs efficiently.
- Implement real-time updates with WebSockets for job tracking and notifications.
- Collaborate with designers to create pixel-perfect, accessible interfaces using Tailwind CSS and shadcn/ui.
- Optimise performance: code splitting, lazy loading, and bundle size reduction.
- Implement form validation with React Hook Form and Zod, and efficient server state management via React Query.
- Build interactive data visualisations for analytics and reporting
- Experience working with machine learning and AI

This role is fully onsite in Castle Hill and requires you to already hold a valid working visa in Australia. Sponsorship is not provided.

Codematix is a recruitment agency. You can find out more about Codematix by visiting codematix.com.au

📌 Senior Full-Stack Developer (Castle Hill)
🏢 Codematix
📍 Castle Hill