Gayan Sanjeewa

Senior Java Developer

📍 Cyberjaya, Malaysia | 🇱🇰 Sri Lankan | 🇲🇾 EP Category 1

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About Me

GS

Senior Java Developer

9+ Years Experience

📞 +60142338986

✉️ slgayan1@gmail.com

🏢 Legally authorized to work in Malaysia

I have over 9 years of career experience in software engineering developing enterprise level applications. Proficient in Java ecosystem and related frameworks with microservice architecture and system integration.

As a collaborative team player committed to continuous learning and driving technical excellence, I specialize in building scalable microservices, implementing CI/CD pipelines, and working with cloud technologies like AWS, OpenShift, and Azure Kubernetes Service.

Currently working as a Senior Java Developer at Aleph-Labs Malaysia for UOB Bank Singapore, where I lead critical development initiatives and manage high-priority production incidents while maintaining strict SLA adherence.

My expertise spans across various domains including banking solutions, enterprise service bus architectures, and fintech applications, with a strong focus on performance optimization and system reliability.

Technical Skills

Core Technologies

Java EE Java SE Spring Boot Spring MVC Spring Security Microservices

Databases & Data

Oracle PostgreSQL MySQL H2 Redis Data JPA MyBatis

Cloud & DevOps

AWS OpenShift Azure AKS Docker Kubernetes CI/CD Jenkins

Tools & Frameworks

Maven Lombok JUnit Mockito Log4j OpenAPI OAuth2

Development Tools

IntelliJ IDEA Eclipse Git Bitbucket GitHub Jira Postman

Monitoring & Analytics

Splunk Grafana Prometheus ELK Stack OpenTelemetry

Work Experience

Senior Java Developer
Aleph-Labs - Malaysia (Client: UOB Bank Singapore)
Oct 2024 – Present
  • Worked closely with System Analyst (SA), Functional Business Analysts (FBA), and Technical Delivery Manager (TDM) to deliver OCN project aligned with business goals
  • Designed and developed new features across multiple Java-based microservices using Spring Boot, REST APIs, and feature toggles under trunk-based development strategy
  • Enabled seamless deployments through CI/CD pipelines (Jenkins) and feature flagging for Malaysia, Singapore, and Hong Kong releases
  • Led key development to decouple critical microservices from database dependencies, migrating to API-based communication
  • Managed high-priority production incidents with strict SLA adherence, responding to SL1, SL2, and SL3 defects
Technologies: JavaEE, Spring Boot, Microservice, Oracle, H2, MyBatis, Log4j, Maven, Lombok, CI/CD, Jenkins, OpenAPI
Senior Backend/Java Developer - ESB
DHL Information Services (Asia-Pacific) - Malaysia
Mar 2023 – Sep 2024
  • Developed highly available and scalable microservices based on business requirements
  • Maintained existing SOAP services and onboarded change requests for current implementations
  • Created and maintained CI/CD pipelines for OpenShift Cloud and Azure Kubernetes Service (AKS)
  • Delivered knowledge transfer sessions and mentored new joiners on key technical areas
  • Responsible for performance testing and resource benchmarking of new microservices
  • Managed end-to-end microservice development from design through production deployment
Technologies: JavaEE, Spring Boot, Oracle, H2, Redis, PostgreSQL, Docker, Kubernetes, OpenShift, AKS, Splunk, Grafana
Senior Software/Java Engineer
Aeturnum Lanka (Pvt) Ltd - Sri Lanka
Dec 2021 – Mar 2023

Multiple Client Projects:

  • MODIFI: Completed code refactoring of microservices, implemented third-party API integrations, worked with German product managers
  • FINCH MONEY: Integrated Astra and Plaid APIs, developed comprehensive unit test cases using JUnit4 and Mockito
  • TIMEMATE: Internal project for employee time tracking, created base projects for microservices, implemented OAuth2 authentication
Technologies: JavaEE, Spring Boot, OAuth2, Spring Security, PostgreSQL, MySQL, AWS, Elasticsearch, Grafana, Prometheus
Software Engineer
Epic Technology Group - Sri Lanka
Nov 2017 – Dec 2021

Key Projects:

  • NDB NEOS (Mobile Banking): Developed SWITCH core component, integrated core bank and CMS with ISO8583 messages
  • CDB Digital Banking: Engineered RESTful APIs for mobile app and admin panel integration
  • TLE (Terminal Line Encryption): Developed admin panel, introduced Hibernate, implemented POS machine transactions
Technologies: JavaEE, Core Java, ISO8583, Oracle, Socket Programming, Struts2, Hibernate, Spring Boot, Redis, AWS
Associate Software Engineer
Boswin Group - Sri Lanka
Dec 2016 – Nov 2017
  • Involved in R&D and PHP development as career starting point
  • Learned AngularJS and mobile development with Android and Ionic
  • Worked on WordPress and PrestaShop projects
Technologies: JavaEE, SpringMVC, PHP, WordPress, PrestaShop, Android, AngularJS, Ionic

Education & Certifications

🎓 Education

BEng (Hons) In Software Engineering (Second Upper)

London Metropolitan University, UK

Jan 2022 - Mar 2023 | TopUp Program

GDSE (Graduate Diploma In Software Engineering)

IJSE (Institute of Java Software Engineering), Sri Lanka

2015 - 2017

🏆 Awards

Overall Bronze Award - NBQSA 2018

Excellence Award from Dr Nayan Dehigama (Executive Chairman) for Terminal Line Encryption (TLE) Project

📜 Recent Certifications

AWS Solution Architect Associate
View Certificate
Kubernetes for Java Developers
View Certificate
Extending, Securing, and Dockerizing Spring Boot Microservices
View Certificate
Running Spring Boot in Production
View Certificate
Software Architecture: From Developer to Architect
View Certificate
Microservices: Design Patterns
View Certificate

Get In Touch

📧

Email

slgayan1@gmail.com

📱

Phone

+60 14-233 8986

💼

LinkedIn

its-me-gayan

💻

GitHub

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