Top Java Developer Jobs in Sydney

Design and develop high-performance backend services for an AI-powered trading assistant: build AI agent execution, trading order execution, AI sub-account and API key lifecycle management, integrate Binance trading APIs, implement skills/tool-calling frameworks, and ensure scalable, low-latency real-time data pipelines, observability, and security.

Design, develop, and maintain high-performance, secure Java backend services and APIs. Ensure reliability, scalability, and cost-efficiency across microservices, databases, messaging systems, and capacity planning. Troubleshoot, profile, benchmark, and optimize systems (including ML applications) and collaborate with Kazakhstan stakeholders.

Lead design and development of scalable backend services in Java, collaborate with PMs and designers to deliver end-to-end product features, drive architecture and reliability improvements, write well-tested production code, mentor peers, participate in code reviews and on-call rotations, and improve service observability and performance.

Work on backend services powering scalable user experiences: design and implement features, build and maintain services, write well-tested code, improve performance and observability, collaborate cross-functionally, participate in code reviews, and use AI tools to enhance development.

The Senior Software Engineer will design and build scalable applications, contribute to architecture, mentor engineers, and improve system reliability.

Design, build, and evolve core backend frameworks, shared services, and developer APIs to accelerate product development. Deliver scalable, maintainable systems, improve observability and rollout processes, collaborate with product teams, and mentor engineers to raise engineering standards across the platform.

Design, build and own core authorization and access-control components (SpiceDB-backed). Drive adoption across product teams, design patterns and tooling, ensure high-availability infrastructure, partner with Security and platform teams, shape identity and access models (including for AI workflows), and mentor engineers on system design and IAM best practices.

Contribute to design, development, and maintenance of real-time risk control and decisioning services. Implement risk rules, scoring models, and feature pipelines for fraud, AML, and account security. Troubleshoot issues, write technical documentation, and collaborate with Risk Operations and CS teams to investigate cases and improve systems.

Develop and maintain low-latency, high-throughput electronic trading infrastructure across the execution stack (order management, client and exchange connectivity, algo trading, smart order routing). Build core technical infrastructure, ensure capacity/resilience/BCP, improve SDLC through automation, and support test engineering and quality assurance for global equities trading systems.

Design and build core backend modules for a high-volume P2P marketplace, including order matching, escrow, dispute resolution, and merchant management. Develop high-concurrency transaction processing, seller/buyer workflows, payment integrations, and ensure reliability, idempotency, and consistency across transactions. Participate in architecture design, code reviews, and cross-team collaboration.

Design, build, and maintain bank and card payment integrations and high-availability, high-concurrency payment processing modules (routing, clearing, reconciliation, settlement). Collaborate with product, risk, and compliance, participate in code reviews and system design, and optimize system performance and scalability.

Design, develop, and optimize high-performance Java backend systems. Contribute to architecture, implement core modules, troubleshoot production issues, perform code reviews, and improve scalability, availability, and reliability of distributed financial or blockchain systems.

Lead QA automation for Futures across web, desktop, and mobile: design and execute test plans, set up test environments, write automated tests, perform security and performance testing, root-cause analysis, and improve testing processes across the SDLC.

Design and build backend microservices for real-time fraud detection, transaction monitoring, and risk analysis. Integrate ML models and risk scoring engines, support scalable distributed systems, and leverage AI-assisted development and LLM/agent tools for risk automation.

Senior QA Automation Engineer responsible for designing, building, and maintaining Rust/Java-based automated test frameworks. Participate across the SDLC to create test plans, execute black-/white-box, security, performance, and mobile testing, diagnose root causes, and improve testing processes. Collaborate with engineers, PMs, designers, and operations to ensure system reliability across web, desktop, and mobile platforms. Apply AI models in testing where applicable and coordinate with global stakeholders in English and Mandarin.

Design and implement complex backend services for Binance Square. Collaborate with product, DevOps, and QA to deliver high-quality microservices, promote engineering best practices, and perform code reviews.

Design and build Java backend systems for on-chain payment flows, integrating wallets, broadcasting and tracking transactions, connecting banking channels to on-chain liquidity, ensuring reliability, idempotency, and handling chain edge cases.

Design and develop scalable software solutions, collaborate with team members, and ensure highest quality standards through best practices in software development.

The Senior Java Engineer will design complex systems, optimize performance, maintain code quality, and ensure application reliability. Responsibilities include translating requirements into applications and troubleshooting issues.

Design, develop and deploy server-side components and real-time data feeds using Java/J2EE/EJB. Ensure database performance, reliability, security and availability. Develop, monitor and optimize EJB and other server-side components while following SDLC practices and contributing to system architecture.

The Senior Backend Engineer will develop distributed web applications, mentor other engineers, and lead complex architectural changes for Canva's products.

The Senior Software Engineer will build APIs and tools, improve production systems, reduce technical debt, mentor others, and work on both backend and frontend code.

Optimize and scale blockchain node performance, design and implement core system plugins, collaborate with cross-functional teams, perform performance testing and debugging, and stay current with blockchain infrastructure trends.

Develop and maintain Java backend services for enterprise blockchain applications, integrate APIs with React/Vue frontends, design scalable blockchain solutions, troubleshoot complex backend issues, and collaborate with cross-functional teams while staying current with blockchain best practices.

Design, implement, and maintain backend systems for a centralized exchange (CEX). Lead architecture and development of payment systems, trading matching engines, real-time compute and middleware platforms. Drive technical reviews, troubleshooting, refactoring, and mentoring to ensure system stability, performance, and engineering standards.