Senior Java Backend Developer

NETS; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

NETS is seeking a seasoned Java backend engineer to design, develop, and maintain scalable services for high-volume transactions and international payment gateway integrations.

You will implement secure APIs, contribute to architecture, and work with DevOps on CI/CD. Strong collaboration across teams is required for reliable, low-latency systems.

Qualifications

• Bachelor’s degree in Computer Science, Software Engineering, or related field.

Responsibilities

• Design, develop, and maintain scalable backend systems for high-volume transaction processing and international payment gateway integrations.

Skills

Java backend development

Microservices

REST API design

Event-driven architecture

Load testing

Troubleshooting

Education

Bachelor’s degree in CS/Software Engineering

Tools

Maven

Git

Jira

Jenkins

MySQL

JUnit/Mockito

Job description

• Design, develop, and maintain scalable backend systems for high-volume transaction processing and international payment gateway integrations.
• Develop secure and high-performance APIs for internal and external system integration.
• Write clean, maintainable, and testable code following engineering best practices.
• Contributes to architecture design for scalable, resilient, and fault-tolerant systems.
• Implement event-driven and asynchronous processing for backend services.
• Support integration across multiple internal and external platforms.
• Design and implement message-driven architectures using enterprise messaging systems.
• Optimize application, database, and service-level performance.
• Perform load testing and identify system bottlenecks.
• Troubleshoot production issues and perform root cause analysis (RCA).
• Ensure system stability and reliability in high-throughput environments.
• Work closely with DevOps teams to support CI/CD pipeline implementation.
• Manage build, deployment, and release processes across environments.

Requirements:

• Bachelor’s degree in Computer Science, Software Engineering, or a related field.
• 6–9 years of experience in Java backend development.
• Strong proficiency in Java 8+ (preferably Java 21) and Spring Boot.
• Proven experience with microservices architecture, event-driven architecture, and REST API development.
• Hands-on experience with messaging systems, preferably Solace.
• Strong experience with MySQL, including database tuning, SQL optimization, indexing, and query tuning.
• Experience with unit testing frameworks such as JUnit and Mockito.
• Proficiency in Maven, Git, Jira, and Jenkins-based CI/CD pipelines.
• Experience in load testing, performance testing, and backend optimization.
• Strong troubleshooting and debugging capabilities, including production issue resolution and root cause analysis.
• Proven experience in e-commerce, banking, or other high-volume transaction environments.
• Strong experience building distributed, scalable, and high-availability systems.
• Hands-on experience implementing microservices and event-driven architecture in production environments.
• Experience handling performance-critical and real-time backend systems.
• Demonstrated ability to work in production support and critical incident resolution environments.