Ralf Köster
Senior Java Developer, Consultant
Experience
Senior Java Developer, Consultant
Dataport AÖR
- Maintenance and further development of the Java/Swing-based @rtus FormsEditor
- Design and development of a graphical formula editor based on Google Blockly to map a project-specific DSL, including parsing and code generation
- Implementation of pixel-perfect synchronization between editor and print preview to improve user experience
- Technologies: Java 17/21, Swing, JavaFX, JBoss/Wildfly, JUnit, Mockito, Blockly, JPedal, ICEPDF, Eclipse
Senior Java Developer, Consultant
ING DiBa
- Maintenance and modernization of legacy systems (Ramon, SODA)
- Conducting performance analyses and implementing tuning measures
- Improving code quality by creating and extending JUnit tests
- Technologies: Java 8/11/17, Wicket, Tomcat, Jetty, Oracle 19c, Hibernate, JPA, JUnit, Mockito, Maven, Git, IntelliJ IDEA
Senior Java Developer, Consultant
DB Systel GmbH
- Ensuring operation and continuous further development of several critical legacy systems (EWD-LSO, TRACE, etc.)
- Migration and modernization of Java applications from Java 8 to 11
- Technologies: Java 8/11, JBoss EAP 7.4, Swing, JSF (RichFaces), Oracle 19c, Hibernate, JPA, Docker, Jenkins, AWS
Java Developer, Design
DB Systel GmbH
- Developed a solution for consistency checking of a complex data model
- Designed and implemented a system for importing and distributed calculation of schedule data
- Identified and resolved performance bottlenecks through systematic profiling
- Technologies: Java 1.7, JBoss EAP 6/7, JSF (RichFaces), Oracle, Hibernate, JPA, REST, YourKit Profiler, Docker
Java Developer, Consultant
Deutsche Bank AG
- Onboarding applications from Postbank and Deutsche Bank into the central configuration and deployment system
- Further development of system components, including a Swing-based submission support tool
- Developing a data migration solution for migrating legacy data into the newly developed configuration management solution
- Technologies: Java 1.7, Swing, JSF (RichFaces), Wicket, Tomcat, Oracle 11, Hibernate, JPA, Maven
iOS Architect & Developer
AirBerlin (for Sevenval GmbH)
- Design and architecture of a hybrid app (iPhone/iPad) combining web content with native iOS features
- Technologies: Objective-C, Xcode
Architecture consulting & development
WildGigs GmbH
- Architecture consulting for system renewal and prototype development, including SAP interfaces (SOAP/JEE)
- Technologies: Java/JEE, SOAP, Apache CXF, Spring
Partial Project Lead & iOS Development
VWD/Gevasys
- Leadership of the iOS team and development of a framework for creating financial information apps
- Technologies: Objective-C, Xcode
Architecture & Development
Deutsche Bank Global Markets
- Development of reporting tools and admin clients in a high-performance financial environment
- Technologies: Java, JSP, Comet, Ajax, jQuery, Tibco
Architecture & Development
Vodafone D2 (for CGI)
- Integration of ATG Outreach for eMarketing campaigns and linking to LDAP user management
- Technologies: Java/JEE, ATG Commerce Suite 2006.3, Oracle 10g
Architecture & Development
DB Fleet Service
- Developed a migration strategy to replace legacy systems with a service-oriented architecture (SOA) based on Eclipse RCP, Spring, and Hibernate
- Technologies: Java, SOA, Eclipse RCP, Spring, Hibernate
Architecture & Development
DAB Bank
- Architected and developed a new securities trading application based on the ATG Dynamo Suite
- Performed performance analysis and fixed a memory leak
- Technologies: Java/J2EE, ATG Dynamo 6.4, Oracle
Architecture & Team Lead
TUI Infotec
- Analyzed and designed a reusable, multi-tenant portal framework for TUI brands with a focus on component-based development
- Technologies: Bea Weblogic 8.1, Java/J2EE, Struts/Tiles
Concept & Development
T-Online
- Designed and developed a portal framework including a shopping solution and automated UI tests
- Technologies: Java/J2EE, Weblogic, Struts, JUnit, Cactus
Architecture & Development
Dresdner Bank AG
- Architected and developed a transaction banking portal and an internet securities trading application
- Technologies: Java/J2EE, EJB, JSP, Bea Weblogic, Struts
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 Information Technology (10 years), Banking and Finance (6 years), Government and Administration (2.5 years), Transportation (2.5 years), Telecommunication (2 years), and Tourism (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 (18.5 years), Product Development (3 years), Business Intelligence (1 year), Project Management (0.5 years), and Quality Assurance (0.5 years).
Summary
As an experienced freelance graduate computer scientist with over 25 years of project experience, I develop concepts and architectures for demanding, pragmatic, and sustainable software solutions for companies.
My technology focus is on complex systems in the Java/JEE environment, from service-oriented architecture (SOA) to the implementation of backend services and web portals. In addition, I have extensive expertise in native iOS app development using Objective-C and Cocoa Touch.
In projects, I take on the role of architect, senior developer, or technical lead of teams (up to 10 people).
My broad industry experience in sectors such as public services, banking, insurance, telecommunications, and logistics enables me to quickly get up to speed in new domains.
Skills
Architecture & Design: Service-oriented Architectures (Soa), System Migration, Solution Design For Complex Java/jee Applications And Mobile Apps.
Java Backend Development: Many Years Of Expertise In Java Enterprise Edition (Jee), Spring, Hibernate/jpa, And Developing Web Services (Rest/soap).
Mobile Development: Design And Implementation Of Native Ios Applications (Iphone/ipad) Using Objective-c And Cocoa Touch.
Portal & Cms Technologies: Deep Experience With Enterprise Solutions Like Atg Dynamo Commerce Suite And Coremedia.
Technical Project Management: Coordination Of Development Teams, Requirements Analysis, Interface Definition, And Quality Assurance.
Databases & Performance: Designing Data Models, Performance Analysis, And Optimization Of Applications And Database Queries.
Programming Languages: Java (Expert), C (Expert), Objective-c, Sql, C++ (Basic Knowledge)
Java Frameworks & Libraries: Jee, Spring, Hibernate/jpa, Jsf (Richfaces), Wicket, Swing, Apache Cxf, Junit, Mockito, Jakarta Struts, Jax-ws
Mobile Frameworks: Cocoa Touch, Uikit, Routeme
Application & Web Servers: Jboss/wildfly, Apache Tomcat, Bea Weblogic, Jetty
Databases: Oracle (10g - 19c), Postgresql, Mysql, Sqlite, Ms Sql Server
Special Know-how: Atg Dynamo Commerce Suite (Dps, Dss, Das, Outreach), Coremedia Cap
Tools & Ides: Intellij Idea, Eclipse, Xcode, Git, Subversion, Maven, Ant, Jenkins, Docker
Operating Systems: Linux, Unix (Hp-ux, Aix, Solaris), Macos, Windows
Languages
Education
University of Applied Sciences
Diploma in Computer Science (FH) · Computer Science
Profile
Frequently asked questions
Do you have questions? Here you can find further information.
Where is Ralf based?
What languages does Ralf speak?
How many years of experience does Ralf have?
What roles would Ralf be best suited for?
What is Ralf's latest experience?
What companies has Ralf worked for in recent years?
Which industries is Ralf most experienced in?
Which business areas is Ralf most experienced in?
Which industries has Ralf worked in recently?
Which business areas has Ralf worked in recently?
What is Ralf's education?
What is the availability of Ralf?
What is the rate of Ralf?
How to hire Ralf?
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 Senior Java Developer, Consultant
Nearby freelancers
Professionals working in or nearby Frankfurt am Main, Germany
