Senior Full Stack Engineer – Kotlin / Spring Boot / React Sydney | Hybrid | 6-Month Day Rate Contract + Likely Extension We’re partnering with a major Australian enterprise going through significant technology transformation, with a number of greenfield initiatives on the roadmap.

We’re looking for a strong backend-leaning Full Stack Engineer who enjoys solving complex problems, owning outcomes and working across the stack when needed.

The opportunity You’ll work within a modern product engineering environment, building and evolving scalable applications while contributing to new greenfield development.

The backend is centred around Kotlin and Spring Boot , but this isn’t a purely backend role. You’ll need enough frontend capability to comfortably work across modern JavaScript applications, with TypeScript and React particularly relevant.

There’s also a strong focus on how engineers are harnessing AI tooling to improve the way they build software . We’re keen to meet developers already using tools such as Claude Code, Cursor,



Copilot or coding agents to accelerate development, testing, debugging and delivery.

What we’re looking for

- Strong Kotlin / Java and Spring Boot engineering experience
- Genuine full stack capability, with a backend bias
- Exposure to JavaScript, TypeScript and/or React
- Experience building APIs, microservices and distributed applications
- Good exposure to modern AWS or GCP cloud environments
- Engineers actively incorporating AI tooling into their development workflows
- Strong problem-solving skills and the ability to take ownership from idea through to production
- Comfortable working within modern CI/CD and product engineering environments

Initial 6-month day rate contract with a robust likelihood of extension. If you’re a hands-on engineer who enjoys difficult technical problems, modern technology and the opportunity to contribute to genuine greenfield development, I’d be keen to hear from you.

📌 Full Stack Engineer - (Spring / Kotlin / React) (Sydney)
🏢 The Onset
📍 Sydney