Rainer Diekmann - Enterprise Architect and Backend Developer

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Hamburg, Germany

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Experience

Jun 2025 - Present

1 year 4 months

Hamburg, Germany

Enterprise Architecture Management / Backend Software Developer

Polizei Hamburg

Several projects in a police context
Model and document police procedures/projects with Archimate (as-is/to-be) in the context of P20 (BKA)
Create software architectures with microservices
POC development with Springboot/Docker/Kubernetes
Project size: 10 people
Enterprise architecture management with Togaf and Archimate
Backend software development Springboot
DevOps with Kubernetes
Implemented using: Java 17/21, Springboot 3, P20 architecture, Togaf, Archimate

Nov 2024 - Mar 2025

5 months

Hamburg, Germany

Software Architect / Software Developer

Signal-Iduna Asset Management

Application system for asset managers
The application consists of several microservices that collect data via API interfaces and present it through a frontend (Angular Material). The backend uses Java with JEE/DropWizard/Springboot
Project size: 20 people
Architecture creation
Backend software development Java/JEE
Frontend software development Angular Material
Creation of automated tests with Sahi-Pro
Implemented using: Java 21, gradle, Tomcat, Linux, Junit, Mockito, Rest, Kafka, JPA, Hibernate, JEE, Dropwizard, Openshift, SQL Server, Flyway, Liquibase, Postgres, Springboot 3, Json, Jdbc, Jpa, Sprinboot 3, Owasp

Jun 2024 - Aug 2024

3 months

Germany

System Integrator / Integration Lead for SW / (Verification) Test Manager for SW

Rheinmetall

The German Armed Forces are converting their radios in all vehicles from analog technology to digital radio technology
Project size: 5 people
Creation of concepts for systems and subsystems
Execution of requirements analysis and requirements management
Support in negotiating technical content with customers, partners, and suppliers
Support in defining, planning, and controlling work packages (as-is/to-be)
Coordination and creation of key system documents
Execution of technical reviews and audits
Creation of technical decision papers (including make or buy)
Creation of test concepts and test documents
Monitoring current technical trends
System modeling in SysML
Implemented using: SysML, Enterprise Architect, Rhapsody, Doors, CI/CD, Owasp

Mar 2024 - Apr 2024

2 months

Germany

Software Developer

Edeka

Maintenance of legacy application
The application is technically outdated and will be replaced soon. Until then, the application must be kept operational (bug fixing, CVEs, updating third-party libraries)
Project size: 1 person
Bug fixing
Integrate security updates (CVEs)
Update open-source libraries
Implemented using: Java 11/17, Struts, maven, Tomcat, Linux, Junit, Mockito, DBUnit, JMX, Eclipse, http, tcp, SOAP, Rest, Json, Jdbc, Owasp

May 2023 - Dec 2023

8 months

Germany

Software Architect / Consultant

RZF – Rechenzentrum der Finanzverwaltung

KONSENS - LAVENDEL
Private health insurers deliver contributions of their insured members to the BZSt (Federal Central Tax Office). The contributions are assigned to employees via the tax number. Using the LAVENDEL process (KONSENS process), the assigned contributions are delivered to employers
Project size: 30 people
Creation of architecture concepts
Architecture consulting regarding microservices implementation/migration compliant with TZAK-2025 using Springboot, JMS, Kafka, and containerization (Kubernetes)
Prototype implementation PoC regarding migration to microservice architecture (Konsens Appkit, Springboot)
Extension of Lavendel-KDialog with KVPV attributes (Java SWT)
Software quality analysis with SonarCube for the LAVENDEL system
Implemented using: Java 17, Jboss 7.4, Springboot 3, Konsens Appkit, SWT, KDialog, Jira, Confluence, Docker, SOAP, REST, JMS, Kafka, maven, gradle, gitlab, Openshift, MagicDraw, XMLSpy, XML, Oracle, JPA, Hibernate, ISO 27001 BSI basic protection, TZAK-2025, Linux, Junit, Mockito, DBUnit, JMX, Eclipse, http, tcp, SOAP, Rest, BPMN, Quarkus, Cloud Native, Json, XSD, Jdbc, Jpa, , Owasp

Feb 2023 - Mar 2023

2 months

Germany

Software Architect / Software Developer

Atruvia

Atruvia Hub
Atruvia is moving its internal intranet portal to a new portal built with microservice technologies
Project size: 10 people
Architecture consulting on microservice implementation
Implementation of Spring Boot backend (Spring Data JPA)
Implementation of Angular frontend
Implemented with: Java, Spring Boot 3, Jira, Confluence, Docker, REST, Gradle, Jenkins, Angular, OpenShift, Spring Data JPA, ELK Stack, Elasticsearch, MinIO, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, SOAP, BPMN, Flyway, JEE, JBoss, REST, JSON, JPA, , OWASP

Mar 2022 - Dec 2022

10 months

Germany

Software Architect / Consultant

ITZBund

KVPV (ELStAM)
Private health insurers send contributions for their insured persons to the BZSt (Federal Central Tax Office). The contributions are assigned to employees via their tax number. Using the ELStAM process, the assigned contributions are delivered to employers
Project size: 20 people
Created architecture concepts with arc42
Architecture consulting on microservice implementation/migration with Spring Boot, JMS/Kafka and containerization (Kubernetes)
Prototype implementation for PoC regarding connection to ELStAM
Shown migration path for the old monolithic application
Software quality analysis with SonarCube for the old ELStAM system
Implemented with: Java, Spring Boot, Jira, Confluence, ARC42, Docker, REST, Maven, Jenkins, Federal Cloud, JEE 7/8, JBoss 7.4, RabbitMQ, OpenAPI, AsyncAPI, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, SOAP, Apache CXF, BPMN, XML, XSD, JDBC, JPA, , OWASP, consensus

Jan 2022 - Feb 2022

2 months

Germany

Software Architect / Consultant

AOK Krankenkassen

OTS – Online Appointment Service
AOK customers can book appointments at the branch office through an online appointment service
Project size: 10 people
Architecture consulting on microservice implementation with Spring Boot, Angular and Kafka
Prototype implementation
Deployment via Helm charts (Kubernetes)
Implemented with: Java, Spring Boot, Jira, Confluence, Docker, REST, Angular, Maven, OpenShift, Jenkins, ARGO-CD, Helm, Kubernetes, Elasticsearch, ELK Stack, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, BPMN, JDBC, JPA, , OWASP

Apr 2021 - Dec 2021

9 months

Hamburg, Germany

Software Architect / Software Developer

Bundesdruckerei

Organ Donation Register
Implementation of several microservices and portals in the context of the OGR project (Organ Donation Register)
Project size: 30 people
Creation of microservices with Spring Boot
Connection to Keycloak via REST admin API
Implementation of frontend components with Angular
CI created via GitLab
Services deployed on OpenShift via Docker
Architecture consulting on microservice implementation with Spring Boot
Implemented with: Java, Spring Boot, Jira, Confluence, Docker, REST, Angular, Maven, OpenShift, DDD, hexagonal architecture, Keycloak, JPQL, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, SOAP, BPMN, Apache Camel, JDBC, JPA, , OWASP

Feb 2021 - Mar 2021

2 months

Hamburg, Germany

Software Developer

Eon Digital Port

EnergieWächter II – alarm management for energy consumption at municipalities
Extension of the EnergieWächter project: connection of an additional AI component for detecting anomalies in consumption data and generating alerts
Project size: 3 people
Extended the existing Spring Boot service as a REST interface for connecting the AI component
REST API defined via OpenAPI
Data analysis of consumption data with Python and Pandas
CI created via GitLab, service deployed on Azure Cloud via Docker
Implemented with: Java, Spring Boot, Jira, Confluence, Docker, Azure, REST, Data Science, Python, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, SOAP, Flyway, JPA, , OWASP

Jan 2020 - Jan 2021

1 year 1 month

Hamburg, Germany

Software Architect / Software Developer

Eon Digital Port

Robin – creation of offers for concession procedures
Replacement of a VBA solution for generating offer documents in Word with an Angular/Java application
Project size: 10 people
Software architecture defined as a microservices architecture
Definition of the REST API with Swagger
Implementation of Java backend with Spring Boot
Frontend development with Angular
Documentation of the architecture and the API
Requirement definition with Product Owner
Security: authentication/authorization of the application with OAuth2 and JWT
Implemented using: Java, Spring Boot, Jira, Confluence, Docker, Azure, Postgres, REST, Angular, MyBatis, OAuth2, JWT, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, HTTP, TCP, Liquibase, JPA

Nov 2019 - Dec 2019

2 months

Berlin, Germany

Software Developer

Webtrekk

Billing Console – export of billing data
Export of billing data from a web application to NetSuite as a batch and manual export
Project size: 1 person
Java backend extended with CSV export
Angular 1 frontend extended
Requirements defined together with customers
Implemented using: Java, Spring, Jira, Confluence, MySQL, REST, Angular, Linux, JUnit, Mockito, JMX, Eclipse, HTTP, TCP

May 2019 - Oct 2019

6 months

Hamburg, Germany

Software Developer

Eon Digital Port

EnergieWächter – alarm management for energy consumption at municipalities
Analysis of energy consumption data for anomalies and automatic notification when threshold values are exceeded
Project size: 5 people
Spring Boot service defined and created as a batch
Requirements defined with Product Owner
Testing of the application
Pipeline implemented with GitLab and Docker
Agile approach using Scrum
Implemented using: Java, Spring Boot, Jira, Confluence, Docker, Azure, Postgres, REST, Data Science, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse

May 2018 - Apr 2019

1 year

Germany

Software Developer

Ponton GmbH

Enerchain - blockchain in energy trading
Orders in energy trading are persisted and distributed using blockchain technology (Tendermint/Go) via a Java API (jABCI)
Project size: 10 people
Software development supported with Java
Distributed architecture defined using web sockets
Implemented using: Blockchain, Tendermint, Java, Websocket, Angular, Jira, Confluence, Vagrant, Docker, ElaticSearch, Kibana, Linux, JUnit, Mockito, DBUnit, JMX, Eclipse, REST

Apr 2018 - May 2018

2 months

Hamburg, Germany

Software Architect (Review)

Kühne & Nagel

New Shipment Visibility
Analysis of the architecture of Spring Boot-based microservices for shipment tracking
Project size: 15 people (subproject)
Software review of the existing architecture and recommendation for improvements
Code review of the source code
Implemented using: Spring Boot, Java, JPA, Oracle, Spring, REST, JMS, Git, JIRA, Docker, OpenShift

Oct 2017 - Mar 2018

6 months

Quickborn, Germany

Software Developer / Subproject Lead

Comdirect

MiFID II
Advance disclosure of costs for securities orders in the web portal and in the postbox
Project size: 20 people (subproject)
Software development with the bank's own software stack based on J2EE
Support with software tests
Subproject lead for the postbox integration topic
Implemented with: Java EE, JPA, Oracle, Spring, JSF, JMS, git, JIRA, BitBucket, JBoss, tomcat

Apr 2017 - Sep 2017

6 months

Hamburg, Germany

Software Developer / Analyst

Eurogate

COIN
Web application for managing container movements and EDI message processing
Project size: 2 people (subproject)
Development with the customer's own Java framework
Coded PL/SQL procedures
Analysis and concept creation
Implemented with: Java, PL-SQL, JPA, Oracle, Spring, Swing, SWT, JBoss, tomcat

Jul 2016 - Mar 2017

9 months

Germany

Software Architect / Subproject Lead

Hermes

ZSK – Central Service Customer
Development of a central customer service based on a microservice architecture with SpringBoot and ActiveMQ
Project size: 4 people (subproject)
Defined the software architecture based on microservices with Spring Boot
Developed messaging between microservices with JMS
Subproject lead for ZSK
Analysis and concept creation
Authentication via JWT
Agile approach with Scrum
Implemented with: Java, Microservice, Spring-Boot, JPA, JMS, ActiveMQ, Oracle, Docker, git, JIRA

Jun 2015 - Jun 2016

1 year 1 month

Hamburg, Germany

Software Architect / Subproject Lead

Signal-Iduna

MABS – Broker Order Processing System
Migration of broker order processing from MS Access to a JEE/AngularJS web portal application
Project size: 8 people (subproject)
Defined the software architecture based on J2EE
REST API definition
Frontend with AngularJS
Subproject lead
Analysis and concept creation
Implemented with: Java, JEE 7, Websphere, Jira, Confluence, MQSeries, Angular-JS, JPA

Aug 2014 - Jun 2015

11 months

Quickborn, Germany

Software Architect / Subproject Lead

Comdirect

DC – COWIAS integration
Conversion of securities settlement communication from SNA to MQSeries and migration from C to Java/JEE
Project size: 15 people
Software architecture
Software development
Subproject lead
Concept creation (UML modeling)
Implemented with: Java, JEE, JBoss, C, Enterprise Architect, git, Jira, stash, MQSeries, SNA

Feb 2013 - Aug 2014

1 year 7 months

Quickborn, Germany

Test Project Manager

Comdirect

TFE – Trading Frontend
Integration of an external trading frontend into in-house core order processes (OTC, equities, bonds, derivatives)
Project size: 20 people
Test project manager (team of 5 people)
Test execution (manual and automated)
Software development for automated tests
Implemented with: HPQC, Quicktest Professional, Oracle, Java, Splunk

May 2012 - Dec 2012

8 months

Hamburg, Germany

Technical Subproject Manager / Software Architect

Airbus Spares

ECDA – Enhanced Consumption Data Analysis
Forecasting part consumption to determine optimal stock levels using statistics
Project size: 5 people
Technical subproject manager
Architecture definition
Data warehouse design
Software development
Implemented with: Qt, C++, Java, Postgres DB, SQL

Jan 2012 - Apr 2012

4 months

Neumünster, Germany

Release Manager

Panasonic

Car radio development for VW, Audi, Seat, Skoda
Modular infotainment toolkit (MIB) for Volkswagen
Project size: 400 people
Release manager
Planning of integrations and releases
Coordination with build management
Leading the integration team (10 people)
Managing supplier deliveries
Implemented with: MS Project, Jira, Subversion

Oct 2008 - Dec 2011

3 years 3 months

Hamburg, Germany

Technical Subproject Manager / Software Architect

Airbus

@MOST – Systems Engineering
Research project to create a fleet simulation and consumption analysis software for aircraft parts
Project size: 50 people
Technical subproject manager
Architecture definition
Development models
Systems engineering (Sysml, IDEF, MLDesigner)
Software development
Implemented with: Sysml (Rhapsody, MagigDraw), IDEF (Core), simulation tool (MLDesigner, Matlab), Qt, C++, Booch

Oct 2007 - Oct 2008

1 year 1 month

Hamburg, Germany

Technical Subproject Manager / Software Architect

Airbus

Planet Inflight Application - Portal
Portal for the aircraft cabin based on AJAX techniques
Project size: 20 people
Technical subproject manager
Software architecture
Quality assurance
Creation and execution of module and load tests
Implemented with: MS Project, UML, AJAX, Postgres, JEE, Spring, JSF, Hibernate, Dojo, JSON, Android ADT, JMeter

May 2007 - Oct 2007

6 months

Hanover, Germany

Technical Subproject Manager / Software Architect

Bauberufsgenossenschaft

Workflow application
Support of business processes using IBM Workflow Server, Swing clients and JEE application servers
Project size: 200 people
Technical subproject management
Software architecture
Quality assurance
Implemented with: MS Project, Adonis, Innovator, IBM Workflow Server, DB2, J2EE, Hibernate

Jan 2007 - Mar 2007

3 months

Zürich, Switzerland

Business Analyst / Software Architect

Credit Suisse

Basel II – Large Exposure Reporting
Reporting of credit risks and issuer risks at ultimate partner level within the scope of Basel II
Project size: 10 people
Technical design
Business concept, Business Analyst
Software architecture
Quality assurance
Validation of reports using banking knowledge (Basel II)
Implemented with: MS Project, Requisite Pro, Rational Rose, Power Designer, Oracle

Nov 2006 - Dec 2006

2 months

Hamburg, Germany

Release Manager / Project Manager

Hamburger Sparkasse

Migration project Z/OS to Solaris
Migration of host applications to Unix Solaris
Project size: 20 people
Release management
Quality assurance
RBE, software architecture, project management
Implemented with: MS Project, Doors

Apr 2006 - Oct 2006

7 months

Hamburg, Germany

Project Manager / Software Architect

Airbus

NSS-CC cabin architecture
Hardware and software system for providing internet access for passengers
Project size: 30 people
Requirements engineering
Project management
Quality management according to Airbus standards (ABDxxx, DO178B)
Software architecture, systems engineering
Implemented with: MS Project, Doors, UML, SysML, Enterprise Architect

Feb 2005 - Mar 2006

1 year 2 months

Frankfurt, Germany

Business Analyst / Software Architect

Commerzbank

Basel II
Development of a Basel II calculation engine with SAS and creation of a comparison implementation in Java for QIS4 and QIS5
Project size: 20 people
Business analysis (Business Analyst), software architecture, test execution
Validation and verification of the results of the Basel II calculation engine
Implemented with: SAS, Java, VBA, Oracle, DWH, PL/SQL, Crystal Reports

Jul 2002 - Nov 2004

2 years 5 months

Hamburg, Germany

Software Architect / Software Developer

Airbus

Cabin logbook as a web application
Capture and analysis of aircraft defects via a J2EE web application and transfer via web services
Project size: 3 people
Analysis, design, software architecture, development, and test execution
JEE architecture with Struts (MVC), Tomcat, JBoss/WebLogic, EJBs
Report generation via XSLT (PDF)
Implemented with: UML (RUP), Java, J2EE, Struts, Tomcat, XML, XSLT, .NET (C#), Axis, HTML, JavaScript

May 2001 - May 2002

1 year 1 month

Hamburg, Germany

Software Architect / Software Developer

Vereins- und Westbank

Internet connection of a portfolio management system
Connection of a central C++ server to web clients via XML bus (SOAP) and BEA WebLogic cluster
Project size: 2 people
Creation of a connection concept for web-based clients
Evaluation of XML tools (Jaxb)
Development with EJBs on BEA WebLogic, frontend with JSPs
Execution of module and load tests
Implemented with: UML (Together/J), Java, J2EE, JSP, EJB, BEA WebLogic, AbaXX Engines, XML (SAX, DOM, JDOM, XSLT, Jaxb), HTML, JavaScript

May 2000 - Apr 2001

1 year

Munich, Germany

Subproject Lead / Software Architect

Hypovereinsbank

Internet relaunch – banking/trading
Software architecture for the internet relaunch of the retail banking portal with IMS connection and EJBs
Project size: approx. 50 people
Creation of the software architecture
IMS Connect for Java integration
Subproject lead for the trading area (securities account, order system, new issues)
Execution of module and load tests
Implemented with: UML (Together/J), Java, J2EE, JSP, EJB, BEA WebLogic, Struts, HTML, JavaScript

Jan 2000 - Apr 2000

4 months

Frankfurt, Germany

Software Developer / Analyst

Dresdner Bank

Corporate finance portal
Development of an internet portal for corporate customers with focus on internet brokerage
Project size: approx. 100 people
Creation of object model and use cases for internet brokerage
Implementation as server-side components with EJBs
Connection of backend systems via JDBC and MQSeries (Swift MT502)
Implemented with: J2SE, J2EE (JSP, Servlets, CORBA), JDBC, XML, UML, Oracle8i, JBuilder, application server: BEA WebLogic, IBM WebSphere

Dec 1999 - Dec 1999

1 month

Germany

Trainer

SolveIT

Training in OOA/OOD and Java
One-week in-house training (2 days OOA/OOD, 3 days Java)
Project size: 8 training participants
Implemented with: J2SE, SWING, JDBC, Oracle8i, PowerPoint

Mar 1999 - Nov 1999

9 months

Germany

Project Manager / Software Developer

IXL

Support for various web projects
Implementation of an applet solution into a server-side solution using Servlets for a bank
Implementation of websites using Servlets and JHTML
Role: project management, analysis, DB design, development

Feb 1999 - Feb 1999

1 month

Germany

Trainer

Bijou Brigitte

Training in OOA/OOD and Java
Conducted a one-week in-house training twice
Topics: Use cases, class diagrams, Java language scope, JDBC, Swing, JavaBeans, threads
Project size: 5 training participants per training session
Implemented with: J2SE, SWING, JDBC, Oracle8i, PowerPoint

Apr 1998 - Aug 1998

5 months

Oslo, Norway

Software Developer / Analyst

Norwegian Employment Office Oslo

Object-oriented client-server project with OO4GL tool
Application for managing unemployed people with disabilities in Norway
Project size: 20 people
Front-end programming with Visual Parts in Visual Age
Fat client architecture with direct Oracle database access
Implemented with: Visual Age Smalltalk, Rational Rose

Jan 1997 - Jan 1997

1 month

Kiel, Germany

Trainer

Oberfinanzdirektion Kiel

Training in OOA/OOD and Java
One-week in-house training for 3 participants
Implemented with: J2SE, SWING, JDBC, Oracle8i, PowerPoint

Apr 1996 - Jan 1999

2 years 10 months

Hamburg, Germany

Project Manager / Software Architect

Police Hamburg

Object-oriented client-server project with OO4GL tool
Development of the EPOS application for recording and linking events, people, objects, and things
Project size: 3 people
Concept and specification of a government application with Dynasty
Definition of an object-oriented 3-tier architecture
Specification and design of business objects
Implemented with: Dynasty, ERWin, Rational Rose

Nov 1995 - Apr 1996

6 months

Germany

Project manager / Software developer

Shipbuilding – CAD system

Object-oriented client-server project using CORBA
Design of a CORBA implementation (Orbix) to encapsulate PL/1 code in C++ classes
Project size: 3 people
Project management, analysis, design, development
Implemented with: CORBA, PL/1, C++, Orbix

Jan 1994 - Apr 1996

2 years 4 months

Germany

Subproject manager / Software developer

Classification society

Design and implementation of a software system
Development of a software system for reliability calculation for ships (FEM and stochastic methods)
Project size: 2 people
Development of numerical methods (Monte Carlo, stochastic fields)
Implemented with: FORTRAN and C++

Jan 1994 - Apr 1996

2 years 4 months

Germany

Subproject manager / Software developer

Customers in shipbuilding

Several projects for PPS and production automation applications
Customer-specific enhancements for interfaces between PPS and CAD systems
Project size: 2 people
Implemented with: PL/1 and C++

Jan 1994 - Nov 1995

1 year 11 months

Germany

Project manager / Software developer

Shipbuilding – CAD system

Evaluation project for object-oriented databases
Review of OO databases as a replacement for relational databases
Design of a migration strategy
Project size: 2 people
Implemented with: ODMG, C++, Orbix, Objectivity

Industry experience

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

Experienced in Aerospace and Defense, Banking and Finance, Government and Administration, Energy, Manufacturing, and Insurance.

Aerospace and Defense

Banking and Finance

Government and Administration

Energy

Manufacturing

Insurance

Business area experience

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

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

Information Technology

Project Management

Product Development

Quality Assurance

Research and Development

Business Intelligence

Summary

Professional experience in the IT field since 1991.
Since 1999, self-employed freelance work as an IT consultant for various industries.
Active in the areas of software architecture, software development, and testing. Main focus in software architecture is on the design of multi-tier architectures and microservices architectures. In modeling/analysis/design, focus on using object-oriented methods with UML/Sysml and simulation. In data modeling, using the ER method. In object-oriented application development, programming with Java and C++.

Skills

Process Models: Agile Approach, Scrum And Kanban
Database Design: Er Modeling
Software Architecture: Design Of Software Architectures; Certified Isqi Software Architect Foundation Level
Ooa/D, Uml: Certified Omg Uml Professional (Fundamental)
Technologies: Jee Java Enterprise, Microservices (Springboot), .Net
Programming Languages: Java 11/17/21, C#, C++, C, Qt, Pl/1, Javascript/Typescript
Development Environments: Eclipse, Idea, Visual Studio Code
Databases/Db Technologies: Sql And Pl/Sql, Oracle, Sybase, Ms Sql Server, Mysql, Postgres, Data Modeling (Er, Idef), Jpa/Jdbc, Spring Jpa
Operating Systems: Windows, Unix, Linux, Mac Os/X
Application Servers: Tomcat, Jboss, Ibm Websphere
Devops – Continuous Delivery: Docker, Dockercompose, Openshift/Kubernetes, Helm-Charts
Other Technologies/Products: Spring, Springboot, Jms, Kafka, Hibernate Jpa, Jpql, Unit Tests (Junit, Mockito), Swing, Swt, Angular (Spa), Maven, Gradle, Rest (Json), Api Creation With Openapi, Html/Css
Source Control Tools: Cvs, Svn (Subversion), Git, Continuus Clearcase
Experience In Technical Project Management With A Hands-On Mentality, Partly With Staff And Budget Responsibility.
Experience In The Basel Ii Environment, Participation In Qis4 And 5 Of The German Bundesbank.
Experience In Object-Oriented Modeling (Ooa/Ood) With Uml.
Experience In Data Modeling For Relational Databases And Data Warehouses (Dwh) Using The Er Method.
Experience In Using Process Models (Rational Unified Process, V-Model, Extreme Programming, Agile Processes, Scrum And Kanban) In Practical Project Environments.
Experience In The Design And Creation Of Technical Concepts And Client/Server Architectures For The Integration And Migration Of Existing Applications (Legacy, Host) Into New Environments (Internet, Intranet) Using Middleware Technologies Such As Java And C++.
Experience In The Architecture And Development Of Web Applications Using Jee And Microservices.
Experience In Testing: Module Tests With Junit, Stress Tests Of Websites With Jmeter, Development Of Test Cases Together With The Business Department, Execution Of Acceptance Tests.
Experience In Using Numerical Methods To Solve Mathematical Problems (Finite Element Methods, Monte Carlo Simulation, Stochastic Modeling, Finite Difference Methods).
Experience In Building Internet Portals.
Experience As A Trainer, Good Didactic Skills.
Experience In Project Coaching.
Experience In Project Management With Staff Responsibility.
Comfortable With Common Planning Tools.
Team-Oriented Way Of Working.

Languages

German

Native

English

Advanced

Education

Oct 1984 - Dec 1991

University of Hamburg

Degree in Applied Mathematics: Numerical methods for solving partial differential equations for shock waves · Mathematics · Hamburg, Germany

Certifications & licenses

Certified ISQI Software Architect Foundation Level

Statistics

Experience

Total positions 44

Experience in Aerospace and Defense 8 y

Avg length 9 m

Longest experience 3 y 2 m

Global experience

Countries worked in 3 (Germany, Switzerland, Norway)

Primary country Germany

Expertise

Recent roles Enterprise Architecture Management / Backend Software Developer, Software Architect / Software Developer, System Integrator / Integration Lead for SW / (Verification) Test Manager for SW

Main industries Aerospace and Defense, Banking and Finance, Government and Administration

Main business areas Information Technology, Project Management, Product Development

Qualifications

Highest degree Master

Certifications earned 2

Profile

Member since

January 2024

Last update

August 2026

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Frequently asked questions

Have questions? Find more information here.

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

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

Rainer has at least 31 years of experience. During this time, Rainer has worked in at least 20 different roles and for 36 different companies. The average length of individual experience is 1 year and 8 months. Note that Rainer may not have shared all experience and actually has more experience.

Based on recent experience, Rainer would be well-suited for roles such as: Enterprise Architecture Management / Backend Software Developer, Software Architect / Software Developer, System Integrator / Integration Lead for SW / (Verification) Test Manager for SW.

Rainer's most recent position is Enterprise Architecture Management / Backend Software Developer at Polizei Hamburg.

In recent years, Rainer has worked for Polizei Hamburg, Signal-Iduna Asset Management, Rheinmetall, Edeka, and RZF – Rechenzentrum der Finanzverwaltung.

Rainer is most experienced in industries like Aerospace and Defense, Banking and Finance, and Government and Administration. Rainer also has some experience in Energy, Manufacturing, and Insurance.

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

Rainer has recently worked in industries like Government and Administration, Information Technology, and Healthcare.

Rainer has recently worked in business areas like Information Technology, Product Development, and Project Management.

Rainer holds a Master in Mathematics from University of Hamburg.

Rainer has 2 certificates. These include: Certified ISQI Software Architect Foundation Level and Certified OMG UML Professional (Fundamental).

Rainer will be available part-time from September 2026.

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Daily rate avg. 894 €

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Median rate 860 €

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 7 Sep 2026. Actual rates may vary depending on seniority level, experience, skill specialization, project complexity, and engagement length.