Kyu-Wang Lee
Software Architect & Lead Software Engineer
Experience
Software Architect & Lead Software Engineer
Lower Saxony State Tax Office
The goal of BIENE is to provide a unified tax collection program for all states.
Tax collection means collecting the assessed taxes. This involves, for example, handling due dates, documenting incoming and outgoing payments, triggering reminders or refunds. Statutes of limitations and payment notices also play an important role. All payment transactions with banks and the bookkeeping are modeled in BIENE.
Setting up the architecture and coordinating the provision of development and test environments at the Hanover site
Installing and configuring environments on Linux servers (Apache Kafka, PostgreSQL)
Interface management: coordinating and aligning the connection of software products from other departments and their test data
Migration of application server, JDK, Maven project structure
Environment coordination and build management
Implementation of external interfaces
Implementation of functional requirements
Designing and implementing RESTful APIs and OpenAPI specifications
Designing and implementing microservice architecture
Setting up and maintaining CI/CD pipelines
Deploying applications on OpenShift
Creating technical documentation and diagrams
Working with SQL databases (Oracle and PostgreSQL)
Authentication and authorization for application and users
Containerizing the application (automated deployment via CI/CD pipeline)
Software Developer
REWE Systems
The application consists of several components that handle specific tasks for the requirements of Toom Baumarkt (tBM). tBM sends orders in D0.1B format to SCI (Supply Chain Integration), which forwards them to the JSM system. The first component checks which warehouse the message is for. If the order is for warehouse 110, the message is forwarded to the next component for further processing. The next component pushes the order messages into a message queue. The application retrieves the messages asynchronously, reads header data and order items, and writes them to a Postgres database. Several endpoints provide order information. Communication with other systems is done via JMS or REST. The application implements reservation functionality for the orders.
Setting up and configuring the project in GitLab
Configuring the CI/CD pipeline in GitLab (DevOps)
Setting up automatic deployment to Kubernetes (K8s) with Helm charts
Implementing the REST application (Spring Boot) and JMS listeners
Modeling messages with MagicDraw
Implementing the message flow (process)
Modeling the database structures
Setting up and configuring the monitoring tool (Grafana)
Configuring realms and OIDC client in Keycloak (OIDC: OAuth 2.0)
User setup, permissions, and rights management in Keycloak
Integrating and securing the application (Spring Boot) with Keycloak via OIDC
Technical documentation in Confluence
Software Developer
Federal Employment Agency
Work packages are handled interdisciplinary using agile methods (Scrum). Project tasks for VERA include developing the new front end of the system, migrating the application server (WebLogic Server) and JDK, test management, deployment, functional enhancements (e.g., legal changes), and necessary technical updates.
Implementing the new front end according to the UI design
Extending the backend logic for REST communication and external interfaces
Migrating Oracle WebLogic Server from 11gR1 to 12cR2
Moving from Oracle Fusion Middleware to Payara
Upgrading Java Oracle JDK 7 to Oracle JDK 8
Integrating Swagger-Core and Swagger-UI into the REST application
Load testing and performance optimization
Systematically creating unit tests with JUnit (including deriving test cases)
Writing technical user stories and partial concept documents
Analyzing and fixing errors found during system testing
Supporting knowledge transfer by involving internal agency staff
Regular alignment of project results with stakeholders
Software Developer
ITZBund
A pentest was carried out by the BSI for the GSB product page at ITZBund. Critical issues were identified in the GSB software: use of insecurely developed software, use of outdated libraries. The project goal is to fix the issues identified by the BSI concerning the currency of the libraries Spring Boot, Spring Security, Gradle, and Gradle plugins:
Spring Boot 2.2.11 to Spring Boot 2.5.1
Spring Security 2.2.4 to Spring Security 5.5.0
Gradle 5.5.1 (Groovy DSL) to Gradle 7.2 (Kotlin DSL) including Gradle plugins
Upgraded Spring Boot from 2.2.11 to 2.5.1
Upgraded Spring Security from 2.2.4 to 5.5.0
Upgraded Gradle from 5.5.1 (Groovy DSL) to 7.2 (Kotlin DSL)
Software Developer
Dataport
In the information systems product group, applications are developed that access registers of external interface partners (e.g., the Federal Criminal Police Office, Federal Office of Administration, Federal Motor Transport Authority). They consist of 16 web applications that support police officers in researching personal data, vehicle data, firearms ownership and license data, as well as legal procedures. All applications implicitly provide web service interfaces for machine-to-machine communication, e.g., for connecting mobile devices.
Requirements analysis
Implementing the new web applications
Implementing configuration and logging
User management
Documentation in Confluence
Supporting operational activities
Bug fixing (ticket handling)
Quality assurance (automated integration tests and GUI tests)
Presenting in meetings
Software Developer
ITZBund
Further development and maintenance of ELStAM: Responsible for the interface to the IdNr procedure. In the nationwide ELStAM data pool, all data needed for the payroll tax deduction process are stored. The system includes central business logic for creating, storing, and delivering individual ELStAM using multiple application servers and a database management system. ELStAM are generated from the data transmitted by the IdNr procedure and other tax data.
Implementing functional requirements
Analyzing tickets
Debugging and adapting code
Correcting and cleaning historical production data
Refactoring in complex applications: Conducting complex restructurings
Experience working with and modeling large data volumes (bitemporal historization)
Software Developer
DKV Euro Service
Developing a corporate portal in the eMobility team. In collaboration with Innogy, enabling commercial fleet operators to charge electric cars across different providers and receive a single central invoice.
Data and database modeling
Developing UI components with Angular 6
Implementing the HTTP/REST interface with Spring Boot
Software Developer
1&1 Telecommunication SE
Implementing and operating a mail server proxy and client migration. Providing an HTTP/REST interface for sending emails using the MBulk interface and handling operational IT tasks.
Requirements analysis and specification
Implementing the HTTP/REST interface
Client migration
Technical documentation
Quality assurance
Test management: Conducting test plans
Operational support
Software Developer
1&1 Telecommunication SE
Expanding and developing multiple REST services with Spring Boot: COMET Core Service and developing a new microservice with a Vaadin frontend.
Requirements analysis
Implementing the REST interfaces
System maintenance: testing, bug fixing
Creating technical and user documentation
Operational support
Software Developer
SHS Viveon AG
Developing a standard product in the Marketing & Sales area (MaSS): developing, enhancing, and maintaining software modules and future-oriented software architectures.
Load testing, performance tuning, and optimization
Documentation (software interfaces) and high-level support
Requirements analysis and specification
Implementing the specification and automated tests
Integrating the ELK stack (Elasticsearch, Logstash, Kibana) into the application
Consulting on projects and bringing together business and technical requirements
Creating development and user documentation
Software Developer
GK Software AG
Development of a POS system (Omni-Channel POS).
Implementation of interfaces via web services & POS processes
Creation and execution of developer tests
Technical documentation in Confluence
System maintenance: testing, bug fixing
Software Developer
Luftfahrtamt der Bundeswehr
Redevelopment and migration of an old military flight operations system to a new one (ZDmF and ZFÜ).
System analysis, evaluation, and selection of suitable technologies
Implementation of the external data interface & server components (EJB 3.1, JPA 2.0)
Database modeling and data migration to the new data model
Middleware update and client adjustments
Technical documentation
Software Developer
Luftfahrtamt der Bundeswehr
Maintenance and further development of a military flight operations system (ZDmF and ZFÜ).
Gathering and analysis of user requirements
Further development of existing application modules
System maintenance: testing, bug fixing
Technical documentation
Industries Experience
See where this freelancer has spent most of their professional time. Longer bars indicate deeper hands-on experience, while shorter ones reflect targeted or project-based work.
Experienced in Government and Administration (6.5 years), Aerospace and Defense (3 years), Retail (2.5 years), Information Technology (2 years), Telecommunication (1 year), and Energy (0.5 years).
Business Areas Experience
The graph below provides a cumulative view of the freelancer's experience across multiple business areas, calculated from completed and active engagements. It highlights the areas where the freelancer has most frequently contributed to planning, execution, and delivery of business outcomes.
Experienced in Information Technology (13 years), Quality Assurance (5 years), Product Development (3.5 years), Operations (1 year), Supply Chain Management (1 year), and Marketing (1 year).
Summary
I am a Diplom graduate in business informatics with over 15 years of experience in software development in the Java environment and am also a "Certified Scrum Developer (CSD)".
My solid technical knowledge, which I acquired through various projects, my computer science studies, and my strong interest in new technologies, allows me to find pragmatic solutions in project situations.
My expertise covers the following areas of computer science: software development and business intelligence. My main focus is on software development and web programming. Through my professional work and studies, I had the chance to gain extensive knowledge. I have broad experience in:
- Software development: Java, JavaEE, Spring (Spring Boot), Hibernate, DB (Oracle, DB2, MySQL), Eclipse-RCP, GUI (Vaadin, Angular, SWT)
- Web programming: HTML, CSS, JavaScript
I have always worked in software development, so I am familiar with tasks and processes related to project work.
My personal goal is always to deliver very good, on-time, and perfect results.
Skills
Technical Focus Areas
- Over 15 Years Of Software Development In The Java Environment
- Analytical And Problem-solving Skills, Quick Learner, Goal-oriented
Relevant Experience
- Extensive It And Computer Knowledge
- Many Years Of It Project Experience In Various Projects And Industries
- Industry Experience In Retail, Telecommunications & Media, And Public Sector
Industry Knowledge
- Retail
- Telecommunications & Media
- Public Sector
Project Lifecycle
- Requirements Analysis
- Implementation
- Quality Assurance
- Test Management
- Integration
- Migration
- Requirements Management
- It Operations
- Technical Documentation
- Project Management
Consulting Experience
- Technology Introduction
- Agile Consulting
- Platform Introduction
- Technology Selection
- Platform Selection
- Architecture Assessment
- Architecture Consulting
Methods And Process Models
- Scrum
- Kanban
- Extreme Programming (Xp)
Business Process Management
- Business Process Modeling
- Workflow Management
- Business Process Analysis (Eepk)
- Itil (V2)
- Business Process Model And Notation (Bpmn)
- Signavio
Technologies And Languages
- Java 5 - 17
- Web Services (Rest, Soap)
- Json
- Xml, Xsd, Wsdl
- Java Ee (Ejb, Jpa, Jms, Ws)
- Uml2
- Pl/sql
- Sql
- Swt, Vaadin, Swing
- Html, Xhtml 1.1, Css (V1-3)
- Jsf, Jsp
- Xsl (Xslt, Xpath)
- Javascript, Jquery
- Groovy
- Angular 6
- Abap (Sap R/3, Mysap)
- Sas
- C (Ansi C 99)
- C/al (Microsoft Dynamics Nav)
- Dom, Ajax
Frameworks
- Spring: Spring Boot, Spring Data Jpa, Spring Data Mongodb, Spring Data Rest, Spring Security, Spring Hateoas, Spring Mvc, Spring Webflow
- Hibernate
- Eclipse-rcp
- Osgi
- Struts
- Apache Axis2
Databases
- Oracle
- Db2
- Postgresql
- Mysql
- Derby
Servers
- Web Servers: Tomcat, Jetty
- Application Servers: Jboss Eap 7.4 (Wildfly)
- Oracle Weblogic
Development Tools
- Intellij
- Eclipse
- Gitlab
- Git
- Svn
- Cvs
- Ibm Rational Synergy
- Maven
- Gradle
- Ci/cd Pipeline: Jenkins, Bamboo, Gitlab, Bitbucket, Artifactory, Sonarqube, Pmd, Openshift, Devops
- Mysql Workbench
- Sourcetree
- Jira
- Confluence
- Aqua Data Studio
- Sql Developer
- Dbvisualizer
- Reporting Tool (Birt): Business Intelligence And Reporting Tools
- Hp Quality Center
- Camunda Bpm
Additional Skills
- Elk Stack: Elasticsearch, Logstash, Kibana
- Software Architecture: Microservices, Soa
- Refactoring In Large Software Projects: Performing Complex Restructurings
- Data And Database Modeling
- Oop, Aop
- Design Patterns
- Geographic Information System: Luciad Map
- Data Warehouse: Etl
- Data Quality Management
- Search Engine Optimization (Seo)
- Document Management System: Alfresco
- Content Management System: Pirobase 7
- Erp Systems: Sap R/3, Microsoft Dynamics Nav
Languages
Education
TH Köln, Campus Gummersbach
Diplom in Business Informatics · Business Informatics · Gummersbach, Germany
Certifications & licenses
Certified Scrum Developer® (CSD®)
Eclipse E4 RCP Training
Document Management System Training: Alfresco
Profile
Frequently asked questions
Do you have questions? Here you can find further information.
Where is Kyu-Wang based?
What languages does Kyu-Wang speak?
How many years of experience does Kyu-Wang have?
What roles would Kyu-Wang be best suited for?
What is Kyu-Wang's latest experience?
What companies has Kyu-Wang worked for in recent years?
Which industries is Kyu-Wang most experienced in?
Which business areas is Kyu-Wang most experienced in?
Which industries has Kyu-Wang worked in recently?
Which business areas has Kyu-Wang worked in recently?
What is Kyu-Wang's education?
Does Kyu-Wang have any certificates?
What is the availability of Kyu-Wang?
What is the rate of Kyu-Wang?
How to hire Kyu-Wang?
Average rates for similar positions
Rates are based on recent contracts and do not include FRATCH margin.
Similar Freelancers
Discover other experts with similar qualifications and experience
Experts recently working on similar projects
Freelancers with hands-on experience in comparable project as a Software Architect & Lead Software Engineer
Nearby freelancers
Professionals working in or nearby Lindlar, Germany
