Senior Java API Developer

Oxydata; Kuala Lumpur; On-site; MYR 180,000 - 280,000; Full time

Job summary

Oxydata in Kuala Lumpur is seeking a Senior Java API Developer to design, develop, and optimize scalable backend services and RESTful APIs. You will mentor juniors and drive engineering best practices.

The role focuses on building production-grade APIs in cloud/enterprise environments, implementing SOLID, OAuth2/JWT security, and contributing to CI/CD pipelines.

Strong hands-on coding and architectural thinking are essential for success.

Qualifications

• 5+ years of backend development experience.
• Strong Java expertise (8/11/17+).
• Hands-on with Spring Boot, Spring MVC and Spring Security.
• Experience designing RESTful APIs and microservices.
• Solid SQL knowledge (MySQL/PostgreSQL/Oracle) and Hibernate/JPA.
• API security experience (OAuth2, JWT).
• Git, Maven/Gradle experience; Docker and CI/CD familiarity.
• Understanding of concurrency, data structures and multithreading.

Responsibilities

• Design, develop, and maintain scalable RESTful APIs and microservices using Java and Spring Boot.
• Architect secure, high-availability backend systems with performance optimization in mind.
• Implement clean, testable, and maintainable code following SOLID principles.
• Optimize application performance, troubleshoot bottlenecks, and resolve production issues.
• Collaborate with frontend, DevOps, QA, and product teams to deliver high-quality features.
• Participate in architecture discussions and technical design reviews.
• Implement API security standards (OAuth2, JWT, API Gateway policies).
• Ensure code quality through unit testing, integration testing, and code reviews.
• Mentor junior developers and promote engineering best practices.
• Contribute to CI/CD pipelines and DevOps improvements.

Skills

Java

Spring Boot

REST APIs

Microservices

SQL

Hibernate/JPA

OAuth2/JWT

Git

Maven/Gradle

Docker

CI/CD

Cloud (AWS/Azure/GCP)

Kubernetes

OpenAPI/Swagger

Multithreading

Tools

Docker

Git

Maven/Gradle

Swagger/OpenAPI

Kubernetes

Job description

Permanent role, onsite, located in Kuala Lumpur. Eligibility: No visa sponsorship available.

Job Description

We are looking for a highly skilled Senior Java API Developer to design, develop, and optimize scalable backend services and RESTful APIs. You will play a key role in architecting secure, high-performance systems, mentoring junior developers, and driving engineering best practices across the team.

This role requires strong hands-on coding ability, architectural thinking, and experience building production-grade APIs in cloud or enterprise environments.

Key Responsibilities

• Design, develop, and maintain scalable RESTful APIs and microservices using Java and Spring Boot.
• Architect secure, high-availability backend systems with performance optimization in mind.
• Implement clean, testable, and maintainable code following SOLID principles.
• Optimize application performance, troubleshoot bottlenecks, and resolve production issues.
• Collaborate with frontend developers, DevOps, QA, and product teams to deliver high-quality features.
• Participate in architecture discussions and technical design reviews.
• Implement API security standards (OAuth2, JWT, API Gateway policies).
• Ensure code quality through unit testing, integration testing, and code reviews.
• Mentor junior developers and promote engineering best practices.
• Contribute to CI/CD pipelines and DevOps improvements.

Technical Requirements

Must-Have

• 5+ years of backend development experience.
• Strong expertise in Java (8/11/17+).
• Solid experience with Spring Boot, Spring MVC, Spring Security.
• Hands-on experience building RESTful APIs.
• Experience with microservices architecture.
• Strong knowledge of SQL (MySQL/PostgreSQL/Oracle) and ORM frameworks (Hibernate/JPA).
• Experience with API security (OAuth2, JWT).
• Familiarity with Git, Maven/Gradle.
• Experience working with Docker and CI/CD pipelines.
• Strong understanding of data structures, concurrency, and multithreading.

Good to Have

• Experience with Kafka or RabbitMQ.
• Cloud deployment experience (AWS, Azure, or GCP).
• Kubernetes knowledge.
• Experience with API documentation tools (Swagger / OpenAPI).
• Experience in fintech or high-transaction systems.

Soft Skills

• Strong analytical and problem-solving skills.
• Ability to work independently and lead technical initiatives.
• Excellent communication and stakeholder management skills.
• Proactive mindset with ownership mentality.