In my role as a Principal Software Engineer, I focus on empowering teams by:

• Providing technical advice and guidance to empower teams in areas such as networking, environment, legacy systems, CI/CD pipeline, and Kubernetes related topics.

• Engaging in solution-level discussions and strategic decision-making in collaboration with Product and Architecture leaders.

Also, I'm enjoying building automation and applications

• Developing server applications for automation and custom orchestration in Kubernetes clusters.

• Building Istio multi cluster in Primary-Remote and Multi Primary mode. design Networking strategy in Istio multi cluster

• Automating the process of provisioning Kubernetes clusters and deploying applications as part of the provisioning

• Automating package management and distribution for Kubernetes environments.

• Developing CLI tools to simplify workflows

Lead building Kubernetes cluster and echo system that is used by entire Tech group of the company.

• Research and consult the best practice of Kubernetes and Docker native (Cloud Native) architecture.

• Building Kubernetes cluster in Google Kubernetes Engine (GKE) and OpenStack.

• Establishing the user and access management workflow for the Kubernetes through Rancher

• Making the standardized Kubernetes On-boarding process for the application team.

• Providing the tooling for Docker ecosystem, such as Docker Registry, Helm Repository

• Writing the SOP and User guide documentations.

And, I am leading IaC(Infrastructure as Code) of our infrastructure configuration and management.

• Writing Terraform module and custom provider for the GCP, GKE, OpenStack, Kubernetes, BigIP F5, and so on.

Also, I worked for Billing and payment, Productivity and Internal Engineering team as a Software Developer and DevOps engineer by December 2017

• DevOps Champion

• Dockerization the legacy applications.

• Developed the application that transform the data from SAP to SalesForce.

• Design and architecture of Commissioning System.

• Design and develop the system that connect to external systems for B to B.

• Design and develop of next generation Billing and Payment systems.

• Building automated provisioning system with Chef and Ansible.

• Building virtualized container instance with Docker and Packer.

• Provisioning and managing the Amazon AWS instances.

• JVM option tuning for Java Web Application with New Relic monitoring.

• Developed Python application that imports the data into HDFS. Hive and Impala query to perform the data comparison.

I transferred from Rakuten Japan to Rakuten USA for the Java expert position. In my deep understanding and experiences in Java development, I was able to improve quality and development process by implementing an automated building/testing/inspection/deployment process in the team.

As a Team Lead and DevOps Champion :

• Established coding conventions and adopted GitFlow for unifying development process.

• Adopted TDD process in development process such as using Mockito.

• Built and managed the building/testing/deployment/inspection automation platforms with Jenkins, Capistrano, Artifactory, SonarQube, Findbugs, Cobertura, Checkstyle.

• Provided a Maven pom.xml file template which includes must have plugins and settings for unified development process.

Developed Capitomcat Jenkins plugin which deploys the Java WAR application into multiple Tomcat at the same time. It was also great experience to learn opensource culture, documentation, and how I should test, manage and publish the application versions.

https://wiki.jenkins.io/display/JENKINS/Capitomcat+Plugin

Developed a messaging workflow framework which helps implementation of the functionalities and roles for the message producer, consumer, and broker.

• Designed core Java interfaces for roles, such as "produce" and "consume", and functionality, such as "start", "stop", "restart", and "health-check".

• Designed Restful webservice API for message producer and consumer.

• Designed with DAO design pattern for numerous message broker system such as RabbitMQ and ActiveMQ.

• Designed and developed dashboard system which can control each step of message flow through Restful API.

Developed a billing and payment system and integration with the Bank.

• Designed architecture of system, business flow, and data model.

Experiences :

• Java, Spring Framework, Spring Data, Restful API, Apache Camel, Quartz Job Scheduler, RabbitMQ, ActiveMQ, Oracle Database, MongoDB, SQL, Ruby, Linux, JSON, XML, Javascript, Jquery,HTML,CSS.

As an Engineer Leader :

• Advised technical issues and researched new technologies.

• Built and managed the automated testing and build systems in the Travel Service Development Department. Jenkins

• Provided the common development environment for Java developers in the Travel Service Development Department such as Eclipse code template/rules, Maven Repository, Review Board, SonarQube and so on.

• Review the source code and design of architecture for quality improvement.

Lead developer of Multilingual Search Engine and Restful/SOAP API webservice project.

• Design the architecture and data structure.

• Designed the core Java interfaces.

• Researched and conducted POC the performance, reliability, and efficiency of big data database such as MongoDB, Cassandra, and Coherence to determine the database of search engine.

• Java, Spring Framework, MongoDB, Cassandra, Coherence.

In charge of development and service operation for Rakuten Travel domestic travel package reservation service, which combines flight ticket, hotel, and rental car reservation.

• Performance analysis, tuning, and troubleshooting.

• JVM and Oracle SQL query tuning.

• Redesigned the search service with the memory cache system to improve the search performance and reduce system load.

• Developed affiliate flight reservation system for Japan Airlines.

Lead developer of the hotel inventory search API webservice system for B to B.

• Design the architecture and data structure.

• Java, Oracle, Restful/SOAP API.

Implemented the group company wide SSO platform to Rakuten Travel back office systems.

• Developed Java library that implements the SSO service API.

I developed and operated the Rakuten Travel international airline ticket reservation service, which is one of the biggest online airline ticket reservation service in Japan.

• Proposed and developed new features and UX/UI for the service. and got awarded as 2nd winner of Customer Satisfaction at Rakuten Awards Dec, 2009

• Maintaining the application code and servers : Java, JSP, HTML, CSS, Javascript, AJAX, Apache Struts, Oracle Database, CentOS.

• Troubleshooting the service issues.

• Adopted Apache Maven to build same Java development environment among the development team.

• Introduced Apache Maven and JUnit to build automated testing process.