Senior Backend Java Microservices Engineer

Optimum Solutions (Singapore) Pte Ltd.; Singapore; On-site; SGD 120,000 - 180,000; Full time

Job summary

Optimum Solutions (Singapore) Pte Ltd. is seeking an experienced Senior Backend Java Developer with a focus on microservices architecture, distributed systems, and backend engineering.

You will design, build, and scale microservices-based RESTful APIs and enterprise backend components, focusing on service communication, asynchronous messaging, and sound microservice design across the stack. The role emphasizes Spring Boot, Java concurrency, database optimization, and robust API/security

Qualifications

• 5+ years of hands-on Java software development experience.
• Strong knowledge of Collections, Streams API, and concurrency.
• Experience with Spring Boot, Spring Core, Spring MVC, and DI.
• Deep microservices and distributed systems understanding.
• Proficient in SQL tuning, data persistence, and Spring Data JPA.
• Experience with testing (JUnit, Mockito) and TDD.

Responsibilities

• Design, build, and maintain scalable microservices using Java and Spring Boot.
• Implement clean microservice patterns, domain-driven design, and reusable modules.
• Document REST endpoints with OpenAPI/Swagger.
• Leverage concurrency and asynchronous messaging for performance.
• Diagnose memory leaks and GC bottlenecks in containerized environments.
• Model relational and NoSQL schemas for decoupled services.
• Manage data persistence and transactions with Spring Data JPA.
• Write optimized SQL queries and implement caching (e.g., Redis).
• Apply resiliency patterns like circuit breakers, rate limiting, retries.
• Implement API security (OAuth2, JWT) and data sanitization.
• Implement structured logging, health checks, and metrics.
• Write unit tests and participate in code/architecture reviews.

Skills

Java

Spring Boot

Microservices

Multithreading

JUnit/Mockito

SQL

Tools

Spring Data JPA

Redis

CI/CD

Swagger/OpenAPI

OAuth2/JWT

Job description

Optimum Solutions (Singapore) Pte Ltd. is seeking an experienced Senior Backend Java Developer with a focus on microservices architecture, distributed systems, and backend engineering.

You will design, build, and scale microservices-based RESTful APIs and enterprise backend components, focusing on service communication, asynchronous messaging, and sound microservice design across the stack. The role emphasizes Spring Boot, Java concurrency, database optimization, and robust API/security