Software Engineer

• May 2023 - Present

Principal Engineer

• Oct 2019 - Feb 2023

* subject-matter expert(SME) of billing and payer management domain and worked as a developer in a scrum team* Owned the architecture, feature design, development and testing strategy for Financial/Transactions modules* Developed a system to handle very high volumes of real time complex financial transactions* Used my SQL expertise to design database schemas and ensured performance optimization for very large datasets - hundreds of millions of transactions* Ensured code quality by creating and maintaining automation testing framework that enabled frequent code deployment.* Migrated patient management module from legacy system to RESTful API application with SpringBoot* Built FHIR(Fast Healthcare Interoperability Resources ) APIs for patient administration* Managed domain database design and its objects(Stored Procedure, functions and indexes) Show less

Software Engineering Team Lead

• Oct 2017 - Sep 2019

* Led team and delivered high risk projects on time and support other team’s projects such as transaction generation and related data insight* Developed threaded billing modules with RabbitMQ* Maintained scheduled billing jobs * Improved stored procedure and queries to improve performance by adjusting index and improving join conditions* Introduce new unit test for legacy codes and Implement page automation and end to end test with own test framework based on Selenium* Organized sprint activities such as grooming, sprint retrospective, and sprint planning with team members. Also, as a team member, I reviewed PR designed new features for core applications. Show less

Senior Developer

• May 2015 - Sep 2017

* Added new billing feature for exist billing system* Improved stored procedures and functions for system performance* Merged separated US/Canada code into one to easy to maintain and reduced redundancy code* Built an application architect with spring Boots and Hibernate for internal Hackathon

Software Architect

• Apr 2013 - Oct 2014

Initialized and led a development team (6 members) to upgrade an ERP SaaS application that has +10 business modules(HR, MRP, Standard, Account,Sales, Manufacturing, Order, Stock, Trade, Resource, CRM and process) and1,200 views and with built with Visual Basic * Researched new technologies to improve management application and easy to develop. * Architected application framework with Spring Framework and Sencha ExtJS * Built an AJAX call gateway controller that handle all request from UI to service layer * Provided technical guidance and contributed code development standards * Created application patterns/templates and extended 50+ core UI components with ExtJS * Developed various view helpers such as Jasper Report, JSON, and Excel to reduce development time and effort. * Designed business report templates with Jasper Studio and trained it to junior developers * Skills: Java/J2EE, Spring Framework, Tomcat, MS SQL Server, Sencha ExtJS, MyBatis, Jasper Reports, SVN, VB Show less

Senior Developer

• Dec 2011 - Dec 2012

Led a team of The Tanzania Revenue Authority Cargo Management Project and delivered * Gathered user requirements and designed the application with use-cases * Configured and implemented application architecture. * Implemented e-document (Manifest, Clearance) exchanging module withJMS and MQ * Managed common libraries and system admin modules * Created configurable data validating library with the Spring ExpressionLanguage * Planned and performed unit test and integrated test with clients *Skills: Java/J2EE, Spring Framework, JMS, ActiveMQ, Oracle 11g, Tomcat, Jasper, StarUML, Erwin, jQuery, JSP/JSTL, SpEL, Velocity, SVN, Maven/Ant, MyBatis/iBatis Show less

Senior Software Developer

• Dec 2010 - Nov 2011

Lead and developed student management system for online learning management system. Skills: Java/J2EE, Spring Framework, Oracle DBMS, Weblogic, StarUML, Erwin, jQuery, JSP/JSTL Lead and developed student management system for online learning management system. Skills: Java/J2EE, Spring Framework, Oracle DBMS, Weblogic, StarUML, Erwin, jQuery, JSP/JSTL

Senior Developer

• Jul 2008 - Nov 2010

Develop and delivered e-trade related systems, and involved in several projects:Mongolian Customs Automated System Project/ Seoul Korea, Mongolia,2008-2010 * Participated in business requirement gathering meetings and documented user stories * Architected application framework, developed standards * Designed and maintained database scheme with Erwin * Tuned customs operating system and reduced CPU usage by 50% * deployed several projects: * Upgraded e-Document Authority modules f, Electronically Tax Invoice Skills: Java/J2EE, Spring, JMS, ActiveMQ, Oracle 11g, WebLogic,OC4J, Tomcat, StarUML, Erwin, jQuery, JSP/JSTL, SVN, Ant, Velocity, JavaSecurity, PKI, SOAP, iBATIS,MyBatis/iBatis Show less

Senior Developer

• Apr 2002 - Jun 2008

created and managed application framework of e-Learning application and improved delivery processes * Created application framework for Learning Management System(LMS) * Led and developed online learning, sales management and back-office systems * Developed and operated 2002 Busan Asian Games information system (MS Application Center (15 web servers) and 2 x SQL Server in Active-Active) Skills: Java/J2EE, Struts/Tiles, Spring Framework, WebLogic, Tomcat, WebSphere, Jasper, StarUML, jQuery, JSP/JSTL, CVS, Ant, MyBatis/iBatis, VB/ASP, Oracle, SQL Server, PowerBuilder, Fusion Charts Show less