Rolf Mainka - Lead Java Developer for Census Systems

🚀 FRATCH GPT 2.0 - Find freelancers with a single prompt. Now including price benchmarking.

Recommended expert

Lollar, Germany

Check rate

Experience

Mar 2019 - Present

7 years 7 months

Germany

Lead Developer and Reviewer of Specialized Applications for the 2021 Census Project

Federal Statistical Office

Kubernetes, AWS Cloud, Docker, RESTful Services, ActiveMQ, Oracle Advanced Queuing, JBoss EAP, Spring Batch, Git, Keycloak, Kafka, Maven
Set up CI/CD pipelines with Jenkins
Developed automated integration tests
Performed DevOps tasks
Regularly performed static code analyses during development on all releases of the Census specialized applications using SonarQube
Set up an R server for household generation
Set up a Kafka server for the CVTS application
Set up a Keycloak instance
Set up a Jira instance to carry out the Jira migration
Set up an IRI Workbench instance and Cosort for test data creation
Set up test systems for Java web applications with JBoss8, JDK17 and Oracle and MySQL databases
Set up the associated Oracle databases, including functionally relevant data
Identified weaknesses in the technical communication between the specialized applications
Built extensive business and technical knowledge of all Census specialized applications
Supported and advised the departments on Census business processes in pre-production and production
Performed load and performance tests with JMeter and Bash scripting

Sep 2012 - Feb 2019

6 years 6 months

Master Data System

Major Bank in Frankfurt

Architecture, design and implementation of a Java-based master data system for the bank's corporate clients
Developed an online GUI, a batch component (Spring Batch) and RESTful services (Jersey)
Independently designed and developed a Java-based business event message broker unique across the bank
Implemented more than 130 business events to supply other banking systems (tax, online banking, MiFID, CRM, ISIS, eIntegrator, GPM)
Developed the GPM – GlobalParty Manager based on Java and Angular.js
Developed Java-based RESTful services for maintaining business domain models in the master data system
Independently developed the REWORKER component for the delayed delivery of business events
DWH output: Compiled information on parties and party groups using database views for Informatica
Technology stack: FRAME, Rich Faces, Prime Faces, MQ, WebSphere MQ, Spring, Spring Batch, Spring Data, Spring Integration, Spring JMS, Angular.js, Java7/Java8, JAXB, JEE, JUnit, Liberty, RESTful Services, SOAPUI, Oracle12, Maven, Bamboo, Git, TFS, Wicket, WebServices, WorkManager, XML, XSD

Apr 2011 - Aug 2012

1 year 5 months

Further development of the bank-wide intranet application for creating banking transactions

ING DIBA

Further development of the bank-wide intranet application for creating banking transactions
Used Apache Wicket as the framework
Technologies: Apache Wicket, Oracle11, Maven, Java7, JavaScript, Jenkins, Jira

Apr 2008 - Mar 2011

3 years

Technical Project Lead for an Intranet Application for Automated Financial Statement Analysis

Major Bank in Frankfurt

Architecture, design and implementation of an intranet application for automated financial statement analysis and reporting
Designed and coordinated an offshore team regarding the design specifications
Took on a quality assurance role and communicated with the client
Technologies and tools: Spring, Spring Webflows, JSF, Rich Faces, WebServices (JAX-RPC, JAX-WS), JAXB, Java6, Oracle, WebSphere Application Server, JUnit, EasyMock, Maven 2.1.0, Enterprise Architect, ClearQuest, RAD, TestDirector

Oct 2007 - Mar 2008

6 months

Design and Implementation of a Data Warehouse

Dekabank

Developed a reporting application for accounting and risk controlling
System components based on SQL Server 2005 (SSIS, SSAS)
Front-end development for data maintenance and display using C# and SQL Server 2005
Technologies and tools: C#, .NET2.0, SQL Server2005, SSIS

Feb 2007 - Sep 2007

8 months

Design and implementation of a J2EE-based service provider for calling COBOL host services

Major Bank in Frankfurt

Development of a J2EE-based infrastructure for communication between Java applications and COBOL mainframe programs
Maintenance of the infrastructure and the services running on it
Management of several COBOL developers
Technologies and tools: Java, Eclipse, JUnit, Hibernate, Enterprise Architect, Ant, RMI, Axis, WebSphere Application Server, XSLT

Jan 2004 - Jan 2007

3 years 1 month

Implementation of the technical architecture for rating systems

Major Bank in Frankfurt

Implementation of a Java/J2EE-based platform for Basel II rating procedures
Evaluation of rule engines (BlazeAdvisor, JRules) and optimization of the JRules integration
Maintenance of the XML-based part of the platform
Implementation of tasks involving Oracle and Hibernate
Technologies and tools: JRules, BlazeAdvisor, Java, J2Ims, Eclipse, JUnit, Enterprise Architect, Ant, RMI, Axis, Hibernate, WebSphere Application Server, XML, XSLT

Apr 2003 - Dec 2003

9 months

Further development of the GPM, Pre-Approval, and IW products

Major Bank in Frankfurt

Further development of the Java products GPM (Global Position Master), Pre-Approval, and IW (International Watchlist)
Deputy project management
Setup of the Java development and test environment
Coordination of features with the client, implementation, and acceptance
Technologies: Java, Swing, Oracle, WSAD, ClearCase

Jan 2003 - Mar 2003

3 months

Coordination and production launch of the Logistics Support System

Major Bank in Frankfurt

Integration of the LBS purchasing software within Commerzbank as part of the JAA Outsourcing project
Coordination of the provision of application and database servers
Integration of authentication and authorization mechanisms
Preparation of deployment instructions and an operating concept
Product responsibility for subsequent releases and integration of read access to third-party systems via J2Ims
Technologies and tools: J2Ims, WebSphere Application Server, WSAD

Jan 2002 - Dec 2002

1 year

Design and implementation of an IT-controlled order management and billing system

Major Bank in Frankfurt

Development of an IT-controlled order management and billing system for the Central Staff Department for Central and Branch Organization at Commerzbank
Data modeling and creation of a logical data model
Setup and maintenance of the Oracle database and implementation of the data access layer
Development of a data import interface and coordination of data migration with IT production
Performance optimization using PL/SQL scripts
Technologies and tools: Oracle, PL/SQL, WebSphere Application Server, WSAD, SQL-Navigator

Jan 2001 - Dec 2001

1 year

Development of a billing system for the use of digital certificates

Großbank Frankfurt

Development of a testing tool for the Transaction Coordinator in the ComTrust/IDENTRUS project
Use of Java-based technologies such as OCSP and digital signatures for XML documents
Technologies and tools: OCSP, RSA algorithm, XML, digital signature

Oct 1999 - Dec 2000

1 year 3 months

Integration of the Rational ClearQuest software into Commerzbank

Commerzbank AG

Training in Rational ClearQuest and integration into Commerzbank's infrastructure
Creation and implementation of an implementation concept
Consulting as product manager and creation of project-specific workflows
Technologies and tools: Rational ClearQuest, UML

Apr 1996 - Oct 1999

3 years 7 months

Further development of the calculation system for life and health insurance

DBV-Winterthur AG

Development of a test system for quality assurance of DBV-Winterthur's calculation system in Delta
Introduction of several tariffs, including the ÖTV pension
Development of the BAV system for reporting BAV values to the Federal Supervisory Office for Insurance
Technologies and tools: Delta, actuarial mathematics, IPF, OS-1100

Industry experience

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

Experienced in Banking and Finance, Government and Administration, and Insurance.

Banking and Finance

Government and Administration

Insurance

Business area experience

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

Experienced in Information Technology, Quality Assurance, Operations, Project Management, Accounting, and Business Intelligence.

Information Technology

Quality Assurance

Operations

Project Management

Accounting

Business Intelligence

Skills

It Focus Areas:

Analysis, Design, Architecture, Conceptualization And Development
Testing
Technical Project Management
Coordination Of Development Teams

Industries:

Research And Education
Insurance
Banking
Federal Statistical Office

Programming Languages:

Java
Javascript
C
Pascal
C#

Databases:

Oracle 21
Mysql

Products / Tools:

Kubernetes 1.30
Aws Cloud
Angular 17
Angular.Js
Ant
Axis
Bamboo
Blazeadvisor (Rule Engine)
Eclipse
Enterprise Architect
Docker
Git
Hibernate
J2ee
Java 17
Jboss
Jira
Jdbc
Jenkins
Jmeter
Jms
Jrules (Rule Engine)
Jsf
Jsp
Junit
Keycloak
Kafka
Maven
Mq
Node.Js
Puppet
Rational Rose
React Js
Rest (Jersey)
Rmi
Rserve
Spring
Spring Webflow
Rich Faces
Struts
Sonarqube
Swing
Tomcat
Websphere Application Server
Websphere Mq
Webservices
Apache Wicket

Languages

German

Advanced

English

Advanced

Persian

Advanced

French

Advanced

Education

Graduate Mathematician / Computer Scientist · Mathematics / Computer Science

Statistics

Experience

Total positions 13

Experience in Banking and Finance 19.5 y

Avg length 2 y 3 m

Longest experience 7 y 6 m

Global experience

Countries worked in 1 (Germany)

Primary country Germany

Expertise

Recent roles Lead Developer and Reviewer of Specialized Applications for the 2021 Census Project, Master Data System, Further development of the bank-wide intranet application for creating banking transactions

Main industries Banking and Finance, Government and Administration, Insurance

Main business areas Information Technology, Quality Assurance, Operations

Qualifications

Highest degree Master

Profile

Member since

September 2025

Last update

September 2026

Need a freelancer? Find your match in seconds.

Try FRATCH GPT

Frequently asked questions

Have questions? Find more information here.

Rolf is based in Lollar, Germany and can operate in on-site, hybrid, and remote work models.

Rolf speaks the following languages: German (Advanced), English (Advanced), Persian (Advanced), French (Advanced).

Rolf has at least 30 years of experience. During this time, Rolf has worked in at least 13 different roles and for 7 different companies. The average length of individual experience is 2 years and 4 months. Note that Rolf may not have shared all experience and actually has more experience.

Based on recent experience, Rolf would be well-suited for roles such as: Lead Developer and Reviewer of Specialized Applications for the 2021 Census Project, Master Data System, Further development of the bank-wide intranet application for creating banking transactions.

Rolf's most recent position is Lead Developer and Reviewer of Specialized Applications for the 2021 Census Project at Federal Statistical Office.

In recent years, Rolf has worked for Federal Statistical Office.

Rolf is most experienced in industries like Banking and Finance, Government and Administration, and Insurance.

Rolf is most experienced in business areas like Information Technology, Quality Assurance, and Operations. Rolf also has some experience in Project Management, Product Development, and Accounting.

Rolf has recently worked in industries like Government and Administration.

Rolf has recently worked in business areas like Information Technology, Operations, and Quality Assurance.

Rolf holds a Master in Mathematics / Computer Science.

The availability of Rolf needs to be confirmed.

Daily rate distribution

0% 25% 50% 75% 100%

<€640 €800-880 €880-960 €960+

The rates shown represent the typical market range for freelancers in this position based on recent contracts on our platform.

Average rates for similar positions

Rates are based on recent contracts and do not include FRATCH margin.

1000

750

500

250

Daily rate avg. 889 €

The average daily rate is the mean of all daily rates from recent contracts of comparable freelancers on our platform.

1000

750

500

250

Median rate 892 €

The median daily rate is the middle value of all daily rates — half of comparable freelancers charge less, half charge more. Unlike the average, it is barely affected by outliers.

Calculated based on our freelancers’ daily rates as of 26 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.

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 Lead Developer and Reviewer of Specialized Applications for the 2021 Census Project