Ralf Köster - Senior Java Developer, Consultant

Q: Where is Ralf based?

Ralf is based in Frankfurt am Main, Germany .

Q: What languages does Ralf speak?

Ralf speaks the following languages: German (Native), English (Advanced) .

Q: How many years of experience does Ralf have?

Ralf has at least 19 years of experience. During this time, Ralf has worked in at least 9 different roles and for 14 different companies . The average length of individual experience is 1 year and 3 months . Note that Ralf may not have shared all experience and actually has more experience.

Q: What is Ralf's latest experience?

Ralf's most recent position is Senior Java Developer, Consultant at Dataport AÖR .

Q: What companies has Ralf worked for in recent years?

In recent years, Ralf has worked for Dataport AÖR , ING DiBa , and DB Systel GmbH .

Q: Which industries is Ralf most experienced in?

Ralf is most experienced in industries like Information Technology , Banking and Finance , and Government and Administration . Ralf also has some experience in Transportation , Telecommunication , and Tourism .

Q: Which business areas is Ralf most experienced in?

Ralf is most experienced in business areas like Information Technology , Product Development , and Business Intelligence . Ralf also has some experience in Project Management and Quality Assurance .

Q: Which industries has Ralf worked in recently?

Ralf has recently worked in industries like Information Technology , Government and Administration , and Banking and Finance .

Q: Which business areas has Ralf worked in recently?

Ralf has recently worked in business areas like Information Technology .

Recommended expert

Frankfurt am Main, Germany

Experience

Nov 2022 - Jun 2025

2 years 8 months

Germany

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

Jan 2022 - Oct 2022

10 months

Germany

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

Jul 2017 - Dec 2021

4 years 6 months

Germany

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

Jul 2015 - Jun 2017

2 years

Germany

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

Sep 2013 - Mar 2015

1 year 7 months

Germany

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

Jan 2013 - Apr 2013

4 months

Germany

Hybrid

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

Sep 2012 - Mar 2013

7 months

Germany

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

Sep 2011 - Mar 2012

7 months

Germany

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

Dec 2009 - Jan 2011

1 year 2 months

Germany

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

Oct 2007 - May 2009

1 year 8 months

Germany

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

May 2006 - Nov 2006

7 months

Germany

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

Dec 2004 - Aug 2005

9 months

Germany

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

Jun 2004 - Sep 2004

4 months

Germany

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

Dec 2002 - May 2003

6 months

Germany

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

May 2000 - Dec 2001

1 year 8 months

Germany

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

Industry Experience

See where this freelancer has spent most of their professional time.

Experienced in Information Technology, Banking and Finance, Government and Administration, Transportation, Telecommunication, and Tourism.

Information Technology

Banking and Finance

Government and Administration

Transportation

Telecommunication

Tourism

Business Area Experience

See which departments and functions this freelancer has contributed to most.

Experienced in Information Technology, Product Development, Business Intelligence, Project Management, and Quality Assurance.

Information Technology

Product Development

Business Intelligence

Project Management

Quality Assurance

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

German

Native

English

Advanced

Education

University of Applied Sciences

Diploma in Computer Science (FH) · Computer Science

Statistics

Experience

Total positions 15

Experience in Information Technology 10 y

Avg length 1 y 3 m

Longest experience 4 y 5 m

Global Experience

Countries worked in 1 (Germany)

Primary country Germany

Expertise

Recent roles Senior Java Developer, Consultant, Java Developer, Design, Java Developer, Consultant

Main industries Information Technology, Banking and Finance, Government and Administration

Main business areas Information Technology, Product Development, Business Intelligence

Profile

Created

September 2025

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Frequently asked questions

Do you have questions? Here you can find further information.

Where is Ralf based?

Ralf is based in Frankfurt am Main, Germany.

What languages does Ralf speak?

Ralf speaks the following languages: German (Native), English (Advanced).

How many years of experience does Ralf have?

Ralf has at least 19 years of experience. During this time, Ralf has worked in at least 9 different roles and for 14 different companies. The average length of individual experience is 1 year and 3 months. Note that Ralf may not have shared all experience and actually has more experience.

What roles would Ralf be best suited for?

Based on recent experience, Ralf would be well-suited for roles such as: Senior Java Developer, Consultant, Java Developer, Design, Java Developer, Consultant.

What is Ralf's latest experience?

Ralf's most recent position is Senior Java Developer, Consultant at Dataport AÖR.

What companies has Ralf worked for in recent years?

In recent years, Ralf has worked for Dataport AÖR, ING DiBa, and DB Systel GmbH.

Which industries is Ralf most experienced in?

Ralf is most experienced in industries like Information Technology, Banking and Finance, and Government and Administration. Ralf also has some experience in Transportation, Telecommunication, and Tourism.

Which business areas is Ralf most experienced in?

Ralf is most experienced in business areas like Information Technology, Product Development, and Business Intelligence. Ralf also has some experience in Project Management and Quality Assurance.

Which industries has Ralf worked in recently?

Ralf has recently worked in industries like Information Technology, Government and Administration, and Banking and Finance.

Which business areas has Ralf worked in recently?

Ralf has recently worked in business areas like Information Technology.

What is Ralf's education?

Ralf attended University of Applied Sciences for Computer Science.

What is the availability of Ralf?

Ralf is immediately available for suitable projects.

What is the rate of Ralf?

Ralf's rate depends on the specific project requirements. Please use the Meet button on the profile to schedule a meeting and discuss the details.