Job Description

18th September, 2026 n

A leading R&D; company based in Castle Hill are currently seeking a full-stack developer to join their growing engineering team.
n You'll be working within a technically solid R&D; environment, developing and supporting software used across the company's products and systems.
n 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.
n The company are looking for an engineer that's interested in real-world technology and product development, rather than purely web-based projects.
n This is a full-time, permanent position which requires you to be onsite in the Castle Hill office.
n You must have working rights in Australia to be eligible for this position.
Key Requirements:
Backend Development:

API Development & Architecture

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- Design, implement, and maintain RESTful APIs using NestJS , with full OpenAPI/Swagger documentation.
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- Implement secure JWT-based authentication with access/refresh tokens using HTTP-only cookies.
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- Define and validate DTOs with NestJS validation pipes for type-safe request/response contracts.
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- Configure CORS policies , rate limiting (e.g., 40 requests/min/user), and comprehensive request logging.
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- Maintain backward-compatible API versioning , planning for future iterations.
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Asynchronous Processing & Job Queues n
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- Architect and maintain BullMQ queues for background job processing.
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- Handle long-running tasks (e.g., floor plan analysis, ML API integration) with retry and exponential backoff strategies.
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- Monitor queue health, optimise concurrency, and scale processing capacity efficiently.
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Database Design & Optimisation n
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- Design normalised PostgreSQL schemas with proper relationships, constraints, and indexing.
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- Use TypeORM for entities, migrations, and data integrity management.
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- Optimise queries to prevent N+1 issues and ensure sub-second response times.
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- Implement transactional consistency for critical multi-step operations.
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- Work with Google Cloud SQL for high availability, backups, and disaster recovery.
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Cloud & Infrastructure Integration n
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- Integrate with Google Cloud Storage for secure file handling.
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- Manage Redis connections for BullMQ job persistence.
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- Design event-driven systems using Google Cloud Pub/Sub ; implement publish-subscribe patterns, versioned message schemas, and dead-letter handling.
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- Ensure reliable message delivery (exactly-once / at-least-once semantics) and monitor system metrics.
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- Deploy containerised microservices on Google Cloud Run with auto-scaling, health checks, and zero-downtime updates.
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- Build serverless functions (GCF Gen 2) triggered by HTTP, Pub/Sub, Firestore, or Storage events with proper retry, idempotency, and performance optimisation.
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Highly Desirable Skills: n
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- Build responsive, TypeScript-based React.js applications.
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- Good knowledge using Javascript
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- Develop reusable UI components, manage state (Redux, Zustand, or Context API), and integrate backend APIs efficiently.
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- Implement real-time updates with WebSockets for job tracking and notifications.
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- Collaborate with designers to create pixel-perfect, accessible interfaces using Tailwind CSS and shadcn/ui .
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- Optimise performance: code splitting, lazy loading, and bundle size reduction.
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- Implement form validation with React Hook Form and Zod, and efficient server state management via React Query .
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- Build interactive data visualisations for analytics and reporting
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- Experience working with machine learning and AI
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This role is fully onsite in Castle Hill and requires you to already hold a valid working visa in Australia. Sponsorship is not provided.n
nCodematix is a recruitment agency. You can find out more about Codematix by visiting n

📌 Senior Full-Stack Developer (New South Wales)
🏢 Codematix
📍 New South Wales