Senior Java Developer – Spring Boot, Kafka & Banking

Recmatrix Consulting; Sydney; On-site; AUD 140,000 - 190,000; Full time

Job summary

Recmatrix Consulting in Sydney is seeking an experienced Senior Java Microservices Developer for a contract role. You will design, build, and maintain scalable Java microservices using Spring Boot and RESTful APIs to connect digital banking channels with core banking systems.

The role emphasizes Kafka-based event streaming, secure API design, and collaboration with architects, QA, and DevOps. Prior banking/financial services exposure is a plus. On-site Sydney-based contract opportunity.

Qualifications

• 7+ years of hands-on Java development experience.
• Strong Spring Boot, Spring Framework and Spring Security expertise.
• Proven RESTful API and microservices architecture skills.
• Kafka experience with producers/consumers and event-driven design.
• Understanding of API security: OAuth 2.0, JWT, TLS.

Responsibilities

• Design, develop, and maintain RESTful APIs and microservices in Java/Spring Boot.
• Build integration services linking digital banking channels with core systems.
• Develop Kafka producers and consumers for event-driven processing.
• Configure Kafka topics, partitions, and error handling.
• Implement secure APIs and messaging with validation and audit logging.
• Create unit, component, and integration tests to ensure quality.
• Participate in code reviews and follow security and design standards.
• Troubleshoot APIs, Kafka, and backend banking integrations.
• Collaborate with architects, QA, DevOps, and business analysts.
• Support CI/CD pipelines and production releases.

Skills

Java

Spring Boot

Kafka

REST APIs

Microservices

OAuth 2.0

SQL Oracle

Education

Bachelor's degree in CS or related

Tools

Git

Maven

Gradle

Job description

Location: Sydney, NSW, Australia

Employment Type: Contract

Role Overview

We are seeking an experienced Senior Java Microservices Developer for a contract opportunity in Sydney. The ideal candidate will have strong hands‑on expertise in Java, Spring Boot, Apache Kafka, and RESTful API development, preferably within banking or financial services environments.

You will be responsible for building scalable, secure, and reliable microservices that integrate digital banking applications with core banking platforms and downstream enterprise systems.

Key Responsibilities

• Design, develop, and maintain RESTful APIs and microservices using Java and Spring Boot.
• Build integration services connecting digital banking channels with core banking and downstream systems.
• Develop Kafka producers and consumers to support event‑driven and asynchronous processing.
• Configure and optimise Kafka topics, partitions, consumer groups, and error‑handling mechanisms.
• Implement secure API and messaging flows with appropriate validation, exception handling, audit logging, and traceability.
• Develop unit, component, and integration tests to ensure code quality and application reliability.
• Participate in code reviews and follow established security, coding, and microservices design standards.
• Investigate and resolve technical issues across APIs, Kafka messaging, and backend banking integrations.
• Collaborate with architects, business analysts, QA teams, DevOps engineers, and banking subject matter experts.
• Support CI/CD pipelines, automated deployments, release activities, and production troubleshooting.

Required Skills & Experience

• 7+ years of hands‑on experience in Java development.
• Strong experience with Spring Boot, Spring Framework, and Spring Security.
• Proven expertise in RESTful API development and microservices architecture.
• Hands‑on experience with Apache Kafka, including producer/consumer APIs and event‑driven design.
• Familiarity with Spring for Apache Kafka is highly desirable.
• Understanding of API security, OAuth 2.0, JWT, and TLS/mTLS.
• Experience with SQL and relational databases such as Oracle or PostgreSQL.
• Proficiency with Git and build tools such as Maven or Gradle.
• Experience writing automated tests using JUnit, Mockito, and API/integration testing frameworks.
• Knowledge of Docker and containerised application development.
• Exposure to CI/CD tools such as Jenkins, GitHub Actions, or Azure DevOps.
• Experience with application monitoring and observability tools such as Splunk, Grafana, or Application Insights.

Preferred Experience

• Previous experience in banking, financial services, or payments technology.
• Experience integrating digital banking channels with core banking platforms.
• Knowledge of reliable event processing, message retry strategies, and Kafka error handling.
• Experience supporting enterprise applications in production environments.