Backend Developer (Java)

We are looking for a Backend Developer (Java) to join Tosan Techno. In this role, you will view software engineering beyond mere coding and directly contribute to the quality, stability, and scalability of mission-critical backend services across payment, PSP, and banking systems. This opportunity is a great fit for someone who is passionate about server-side architecture, high-concurrency performance optimization, and solving complex technical challenges in sensitive operational environments.

Responsibilities

• Design, develop, and maintain robust server-side (backend) services and modules using Java and the Spring Boot framework.
• Design, implement, and document secure and scalable RESTful APIs for seamless system integration.
• Implement and optimize the data access layer and transaction management using JPA, Hibernate, and Spring Data.
• Design database schemas, write optimized queries, and develop stored procedures within Oracle Database and PL/SQL environments.
• Enhance code quality, readability, and maintainability through continuous code reviews, unit testing, and adherence to Clean Code and SOLID principles.
• Monitor service performance, identify processing bottlenecks, and troubleshoot operational issues in high-transaction production environments.
• Collaborate closely with analysis, QA, infrastructure, and security teams to ensure reliable deployment and system integrity.

Requirements

Must Have

• Deep proficiency in Java (Java 8+), Object-Oriented Programming (OOP), Multithreading, and the Spring Boot ecosystem.
• Hands-on expertise in designing RESTful APIs and working with ORM and data persistence frameworks including JPA / Hibernate and Spring Data.
• Strong experience with relational databases, specifically Oracle Database, and proficiency in PL/SQL programming.
• Strong analytical and troubleshooting skills, with a practical commitment to software engineering best practices (Clean Code, SOLID, and Design Patterns).
• Effective communication and stakeholder management skills across cross-functional teams (analysis, QA, and operations) to manage multiple priorities and deliver on schedule.

Nice to Have

• Familiarity with Microservices architecture, message brokers (such as Kafka or RabbitMQ), and caching solutions (Redis).
• Proficiency with build, version control, and CI/CD tools including Maven, Git, and Docker.
• Prior experience developing backend systems in the banking, payment (PSP), or high-volume fintech domains.

Benefits

• Complementary Health Insurance.
• Employee Loans and Welfare Facilities.
• Learning and Professional Development Budget.
• Flexible Working Hours.
• Professional and Learning-Oriented Work Environment.
• Organizational Gifts and Celebrations.
• Access to Café.
• Lunch Allowance.