Job Description
/n 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 strong 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 /n /n
- Design, implement, and maintain RESTful APIs using NestJS, with full OpenAPI/Swagger documentation. /n
- Implement secure JWT-based authentication with access/refresh tokens using HTTP-only cookies. /n
- Define and validate DTOs with NestJS validation pipes for type-secure request/response contracts. /n
- Configure CORS policies, rate limiting (e.g., 40 requests/min/user), and comprehensive request logging. /n
- Maintain backward-compatible API versioning, planning for future iterations. /n Asynchronous Processing & Job Queues/n /n /n
- Architect and maintain BullMQ queues for background job processing. /n
- Handle long-running tasks (e.g., floor plan analysis, ML API integration) with retry and exponential backoff strategies. /n
- Monitor queue health, optimise concurrency, and scale processing capacity efficiently. /n Database Design & Optimisation/n /n /n
- Design normalised PostgreSQL schemas with proper relationships, constraints, and indexing. /n
- Use TypeORM for entities, migrations, and data integrity management. /n




- Optimise queries to prevent N+1 issues and ensure sub-second response times. /n
- Implement transactional consistency for critical multi-step operations. /n
- Work with Google Cloud SQL for high availability, backups, and disaster recovery. /n Cloud & Infrastructure Integration/n /n /n
- Integrate with Google Cloud Storage for secure file handling. /n
- Manage Redis connections for BullMQ job persistence. /n
- Design event-driven systems using Google Cloud Pub/Sub; implement publish-subscribe patterns, versioned message schemas, and dead-letter handling. /n
- Ensure reliable message delivery (exactly-once / at-least-once semantics) and monitor system metrics. /n
- Deploy containerised microservices on Google Cloud Run with auto-scaling, health checks, and zero-downtime updates. /n
- Build serverless functions (GCF Gen 2) triggered by HTTP, Pub/Sub, Firestore, or Storage events with proper retry, idempotency, and performance optimisation. /n Highly Desirable

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

📌 Senior Full-Stack Developer (Sydney)
🏢 Codematix
📍 Sydney