Fullstack Senior Software Engineer
Aktualisiert am 11.12.2025
Profil
Freiberufler / Selbstständiger
Remote-Arbeit
Verfügbar ab: 01.01.2026
Verfügbar zu: 100%
davon vor Ort: 100%
Java
Spring
SQL
Maven
Hibernate
GWT
PostgreSQL
Spring Boot
JEE
Jenkins
PL/SQL
Git
Java Swing
Docker
Vaadin
MySQL
Scrum
JSF
Oracle
Dart
PrimeFaces
JavaScript
Python
English
medial knowledge
German
fluent
Russian
mother-tongue

Einsatzorte

Einsatzorte

Köln (+50km) Bonn (+20km) Düsseldorf (+20km)
möglich

Projekte

Projekte

2 Jahre 6 Monate
2023-07 - 2025-12

Software architecture, development

Senior Software Engineer JavaEE JSF/PrimeFaces EJB ...
Senior Software Engineer
Software architecture, development
  • Worked on a fiscal and security risk analysis of the customs administration and the investigation services project
  • Maintained and extended a JEE/Spring based risk management system with a JSF/PrimeFaces frontend and Oracle database
  • Except for the daily business as bugfixing and different requirement implementations this are the most interesting parts on which i worked on:
    • worked on a new powerful, Elasticsearch based, search architecture as a replacement for a legacy Oracle DB based solution
    • migrated EJB-Services to Spring
    • migrated RIKO-Application from JBoss-EAP 7.4 to 8.0 together with Spring Boot from 2.7 to 3.3 including Hibernate and major CI/Jenkins adjustments
    • migrated (code rewritten) from deprecated Elasticsearch REST Client Library to the current Elasticsearch Java Client Library
    • optimized huge MS-Excel file import process by switching to streaming technology
  • Supported requirement engineers
  • Supported developer and test colleagues
  • Prepared Oracle DDL scripts
JavaEE JSF/PrimeFaces EJB JPA/Hibernate Spring Boot REST-Services Elasticsearch Oracle DB Maven Jenkins Git IntelliJ IDEA Oracle WebLogic JEE Server JBoss-EAP
Informations- technikzentrum Bund (ITZ Bund)
Hamburg (Germany)
2 Jahre 6 Monate
2021-01 - 2023-06

Software architecture, development

Senior Software Engineer Java proprietary framework MDA ...
Senior Software Engineer
Project for a DIY store
  • Worked on an ERP system project
  • Implemented requirements and bugfixes on an existing ERP system
  • The ERP system based on a proprietary Java framework (TREND-Framework), which was used to extend and create GUIs, implement the business logic and test it

Project for a food-retailer/discounter
  • Worked on a checkout/till and related backoffice system
  • Implemented requirements and bugfixes on an existing codebase based on a proprietary Java framework (TREND-Framework) and tools
  • Main topics were: analyse requirements and bugs, extend and design till process workflows, extend and design reports, extend and design REST and SOAP interfaces for data import/ export, code refactoring, define and write integration and unit tests, documentation, release preparation
  • Worked on a Python script for documentation export from proprietary documentation system (TREND-Analyst) to Atlassian-Confluence
  • Supported developer and test colleagues
  • Participated in code reviews
Java proprietary framework MDA workflow persistence communication GUI) Maven Jenkins PostgreSQL H2 Database Git IntelliJ IDEA Eclipse with proprietary framework related plugins proprietary framework for integration tests (Integrity) proprietary reporting engine OpenAPI plugin for contract first interface definition WildFly Application Server SOAP and REST WebServices OpenAPI Scrum
GEBIT Solutions GmbH
Düsseldorf (Germany)
1 Jahr 2 Monate
2019-11 - 2020-12

Software architecture, development

Senior Software Engineer Java Spring Spring Batch ...
Senior Software Engineer
Software architecture, development
  • Worked on the DAC 6 project (DAC 6: EU tax disclosure rules)
  • Designed and implemented an Application based on Spring Batch Jobs to process tax arrangement data
  • Main topics were: technical sub-system design and documentation, generate large XML files (up to 100 MB) with JAXB, implement Oracle PL/SQL Procedures, Reporting SQL Views, different types of tests (Unit-Test; Integration-Tests; System-Tests; Stress-Tests)
  • Developed a WebApplication GUI with JSF/PrimeFaces with strict accessibility requirements especially for blind users
  • Defined JUnit and Selenium Web-GUI tests
  • Prepared Jenkins jobs
  • Supported developer colleagues
  • Supported test team
  • Participated in code reviews
Java Spring Spring Batch JPA/Hibernate Maven Oracle SQL PL/SQL JSF/PrimeFaces Eclipse Git
Informationstechnikzentrum Bund (ITZ Bund)
Bonn (Germany)
7 Monate
2019-03 - 2019-09

Software architecture, development

Senior Software Engineer PHP Symfony-Webframework Vue.js Spring Boot ...
Senior Software Engineer
Software architecture, development
  • Implemented a GUI for a telecommunication carrier incident management system with PHP Symfony-Webframework and Vue.js
  • Supported the backend team on Spring Boot microservices development
  • Designed an external order interface architecture
  • Implemented a GUI for a product configuration system with PHP Symfony-Webframework and JavaScript
PHP Symfony-Webframework Vue.js Spring Boot REST Services JPA/Hibernate Maven Oracle IntelliJ IDEA Git Scrum
Plusnet GmbH
Cologne (Germany)
4 Jahre 6 Monate
2014-09 - 2019-02

Software architecture, development

Senior Software Engineer Spring Spring Boot JPA/Hibernate ...
Senior Software Engineer
  • Implemented CoreWallet payment gateway integrations for client-specific, local PSPs including corresponding payment method setup and routing
  • Implemented a Processing and Routing Engine for Payments
  • Implemented client-specific SPAs with Ember.js
  • Implemented an SBE test framework and an exhaustive suite of SBE tests for a large client project
  • Software engineer on the CoreWallet, balancr and CoreExchange products
  • Implemented a highly customizable Sport Event Android App
  • Integrated Google Maps and HERE Maps in Android
  • Introduced GPS-Tracking and Video Playback
  • Integrated AWS Push-Notifications/ Amazon Simple Notification Service (SNS)
Spring Spring Boot JPA/Hibernate MySQL PostgreSQL Redis-DB Ember.js Maven REST and SOAP WebServices Jenkins IntelliJ IDEA Android Studio Git Subversion Scrum Kanban
trimplement GmbH
Cologne (Germany)
5 Monate
2014-04 - 2014-08

Software architecture, development

Senior Java Developer GWT Tomcat JBoss
Senior Java Developer
  • Developed on a Deployment/Release Management System
GWT Tomcat JBoss
AXA Konzern AG
Cologne (Germany)
4 Jahre 6 Monate
2009-10 - 2014-03

Software architecture, development

Senior JEE Software Developer Glassfish JEE Application Server EJB Spring ...
Senior JEE Software Developer
  • Developed a Billing System which unified billing data from multiple legacy systems
  • Developed a CRM System
  • Developed several services and tools for Telecommunication typical scenarios (VPN-, Telephony-/ Fax-, Telecommunication Port - Management Systems)
  • Implement Oracle PL/SQL Procedures for data synchronisation
Glassfish JEE Application Server EJB Spring JSF/Richfaces Oracle Maven Ant Jenkins Eclipse
QSC AG
Cologne (Germany)
2 Jahre
2007-10 - 2009-09

Software architecture, development

J2EE Software Developer TIBCO ESB JMS SOAP WebServices
J2EE Software Developer
  • Developed Java Applet, Struts and MS Excel VBA Applications for a natural gas exchange platform
  • Developed a SOA sub system for message interchange with third-parties
TIBCO ESB JMS SOAP WebServices
Atos Origin GmbH
Cologne (Germany)
2 Jahre
2005-10 - 2007-09

Software architecture, development

J2EE Software Developer
J2EE Software Developer
Software architecture, development
  • Developed a highly customizable Billing System for TV-Commercials in context of AdManagement/ Sales System
  • Developed several Data Import/Export interfaces and tools
  • Developed several Data Migration PL/SQL Scripts
  • Developed several Report Data Collectors
S4M - Solution for Media GmbH
Cologne (Germany)
10 Monate
2004-10 - 2005-07

Software development

.NET Software Developer (working student)
.NET Software Developer (working student)
  • Implemented a Industry Roboter Controlling Application on Windows Embedded CE device
mz robolab GmbH
Rheinbach (Germany)
5 Monate
2002-10 - 2003-02

Software development

.NET Software Developer (working student)
.NET Software Developer (working student)
  • Implemented a Sync Web Tool to German Insurance Association (GDV)
Ineas Versicherung GmbH
Cologne (Germany)

Aus- und Weiterbildung

Aus- und Weiterbildung

2000 - 2005
Study - Allgemeine Informatik
Fachhochschule Köln/ Campus Gummersbach
Focus areas: Software Development and Artificial Intelligence (Artificial Neural Networks)
Degree: Diplom

Position

Position

Senior Software Engineer

Kompetenzen

Kompetenzen

Top-Skills

Java Spring SQL Maven Hibernate GWT PostgreSQL Spring Boot JEE Jenkins PL/SQL Git Java Swing Docker Vaadin MySQL Scrum JSF Oracle Dart PrimeFaces JavaScript Python

Produkte / Standards / Erfahrungen / Methoden

PROFILE
The candidate has been developing software for diverse companies and industries. While studying informatics he worked for an insurance company and for an industry roboter company. After his graduation and his prize-winning thesis in AI context he worked for a media corporation, a natural gas industry IT service contractor, a telecommunication company, an insurance company and a FinTech contractor. Since March 2019, he is working as a freelancer and supports his customers as a full-stack senior software engineer. He is team-minded and reliable with a strong focus to deliver high-quality results.

TECHNICAL SKILLS
Java, SQL, PL/SQL, JavaScript, Groovy, C#, PHP, Python, (Dart, Ruby, Go), Spring, Spring Boot, Spring Batch, JEE, JPA, Hibernate, Toplink/EclipseLink, PHP Symfony, JMS, REST, SOAP WebServices, TIBCO ESB, Quarkus, Vert.x, Android, JSF/PrimeFaces, Vue.js, Ember.js, GWT, JSP, Struts, Swing, Java-Applets, HTML, CSS, Polymer-JS, Angular.js, Vaadin, ActionScript/Flex, Elasticsearch, Oracle DB, MySQL/MariaDB, PostgreSQL, Sybase, MS SQL Server, H2, SQLite, Redis, Tomcat, JBoss, Glassfish, Oracle WebLogic, Maven, Ant, Gradle, Git, Subversion, Jenkins, Docker, OpenAPI/Swagger, JUnit, Selenium, Mockito, JMeter, MapStruct, IntelliJ IDEA, Eclipse, Android Studio, VS Code, Google Maps on Android, HERE Maps on Android, Highcharts-JS, WebRTC

Programmiersprachen

Java
JavaScript
Oracle/SQL
PL / SQL
SQL

Datenbanken

MySQL
Oracle
PostgreSQL
H2

Einsatzorte

Einsatzorte

Köln (+50km) Bonn (+20km) Düsseldorf (+20km)
möglich

Projekte

Projekte

2 Jahre 6 Monate
2023-07 - 2025-12

Software architecture, development

Senior Software Engineer JavaEE JSF/PrimeFaces EJB ...
Senior Software Engineer
Software architecture, development
  • Worked on a fiscal and security risk analysis of the customs administration and the investigation services project
  • Maintained and extended a JEE/Spring based risk management system with a JSF/PrimeFaces frontend and Oracle database
  • Except for the daily business as bugfixing and different requirement implementations this are the most interesting parts on which i worked on:
    • worked on a new powerful, Elasticsearch based, search architecture as a replacement for a legacy Oracle DB based solution
    • migrated EJB-Services to Spring
    • migrated RIKO-Application from JBoss-EAP 7.4 to 8.0 together with Spring Boot from 2.7 to 3.3 including Hibernate and major CI/Jenkins adjustments
    • migrated (code rewritten) from deprecated Elasticsearch REST Client Library to the current Elasticsearch Java Client Library
    • optimized huge MS-Excel file import process by switching to streaming technology
  • Supported requirement engineers
  • Supported developer and test colleagues
  • Prepared Oracle DDL scripts
JavaEE JSF/PrimeFaces EJB JPA/Hibernate Spring Boot REST-Services Elasticsearch Oracle DB Maven Jenkins Git IntelliJ IDEA Oracle WebLogic JEE Server JBoss-EAP
Informations- technikzentrum Bund (ITZ Bund)
Hamburg (Germany)
2 Jahre 6 Monate
2021-01 - 2023-06

Software architecture, development

Senior Software Engineer Java proprietary framework MDA ...
Senior Software Engineer
Project for a DIY store
  • Worked on an ERP system project
  • Implemented requirements and bugfixes on an existing ERP system
  • The ERP system based on a proprietary Java framework (TREND-Framework), which was used to extend and create GUIs, implement the business logic and test it

Project for a food-retailer/discounter
  • Worked on a checkout/till and related backoffice system
  • Implemented requirements and bugfixes on an existing codebase based on a proprietary Java framework (TREND-Framework) and tools
  • Main topics were: analyse requirements and bugs, extend and design till process workflows, extend and design reports, extend and design REST and SOAP interfaces for data import/ export, code refactoring, define and write integration and unit tests, documentation, release preparation
  • Worked on a Python script for documentation export from proprietary documentation system (TREND-Analyst) to Atlassian-Confluence
  • Supported developer and test colleagues
  • Participated in code reviews
Java proprietary framework MDA workflow persistence communication GUI) Maven Jenkins PostgreSQL H2 Database Git IntelliJ IDEA Eclipse with proprietary framework related plugins proprietary framework for integration tests (Integrity) proprietary reporting engine OpenAPI plugin for contract first interface definition WildFly Application Server SOAP and REST WebServices OpenAPI Scrum
GEBIT Solutions GmbH
Düsseldorf (Germany)
1 Jahr 2 Monate
2019-11 - 2020-12

Software architecture, development

Senior Software Engineer Java Spring Spring Batch ...
Senior Software Engineer
Software architecture, development
  • Worked on the DAC 6 project (DAC 6: EU tax disclosure rules)
  • Designed and implemented an Application based on Spring Batch Jobs to process tax arrangement data
  • Main topics were: technical sub-system design and documentation, generate large XML files (up to 100 MB) with JAXB, implement Oracle PL/SQL Procedures, Reporting SQL Views, different types of tests (Unit-Test; Integration-Tests; System-Tests; Stress-Tests)
  • Developed a WebApplication GUI with JSF/PrimeFaces with strict accessibility requirements especially for blind users
  • Defined JUnit and Selenium Web-GUI tests
  • Prepared Jenkins jobs
  • Supported developer colleagues
  • Supported test team
  • Participated in code reviews
Java Spring Spring Batch JPA/Hibernate Maven Oracle SQL PL/SQL JSF/PrimeFaces Eclipse Git
Informationstechnikzentrum Bund (ITZ Bund)
Bonn (Germany)
7 Monate
2019-03 - 2019-09

Software architecture, development

Senior Software Engineer PHP Symfony-Webframework Vue.js Spring Boot ...
Senior Software Engineer
Software architecture, development
  • Implemented a GUI for a telecommunication carrier incident management system with PHP Symfony-Webframework and Vue.js
  • Supported the backend team on Spring Boot microservices development
  • Designed an external order interface architecture
  • Implemented a GUI for a product configuration system with PHP Symfony-Webframework and JavaScript
PHP Symfony-Webframework Vue.js Spring Boot REST Services JPA/Hibernate Maven Oracle IntelliJ IDEA Git Scrum
Plusnet GmbH
Cologne (Germany)
4 Jahre 6 Monate
2014-09 - 2019-02

Software architecture, development

Senior Software Engineer Spring Spring Boot JPA/Hibernate ...
Senior Software Engineer
  • Implemented CoreWallet payment gateway integrations for client-specific, local PSPs including corresponding payment method setup and routing
  • Implemented a Processing and Routing Engine for Payments
  • Implemented client-specific SPAs with Ember.js
  • Implemented an SBE test framework and an exhaustive suite of SBE tests for a large client project
  • Software engineer on the CoreWallet, balancr and CoreExchange products
  • Implemented a highly customizable Sport Event Android App
  • Integrated Google Maps and HERE Maps in Android
  • Introduced GPS-Tracking and Video Playback
  • Integrated AWS Push-Notifications/ Amazon Simple Notification Service (SNS)
Spring Spring Boot JPA/Hibernate MySQL PostgreSQL Redis-DB Ember.js Maven REST and SOAP WebServices Jenkins IntelliJ IDEA Android Studio Git Subversion Scrum Kanban
trimplement GmbH
Cologne (Germany)
5 Monate
2014-04 - 2014-08

Software architecture, development

Senior Java Developer GWT Tomcat JBoss
Senior Java Developer
  • Developed on a Deployment/Release Management System
GWT Tomcat JBoss
AXA Konzern AG
Cologne (Germany)
4 Jahre 6 Monate
2009-10 - 2014-03

Software architecture, development

Senior JEE Software Developer Glassfish JEE Application Server EJB Spring ...
Senior JEE Software Developer
  • Developed a Billing System which unified billing data from multiple legacy systems
  • Developed a CRM System
  • Developed several services and tools for Telecommunication typical scenarios (VPN-, Telephony-/ Fax-, Telecommunication Port - Management Systems)
  • Implement Oracle PL/SQL Procedures for data synchronisation
Glassfish JEE Application Server EJB Spring JSF/Richfaces Oracle Maven Ant Jenkins Eclipse
QSC AG
Cologne (Germany)
2 Jahre
2007-10 - 2009-09

Software architecture, development

J2EE Software Developer TIBCO ESB JMS SOAP WebServices
J2EE Software Developer
  • Developed Java Applet, Struts and MS Excel VBA Applications for a natural gas exchange platform
  • Developed a SOA sub system for message interchange with third-parties
TIBCO ESB JMS SOAP WebServices
Atos Origin GmbH
Cologne (Germany)
2 Jahre
2005-10 - 2007-09

Software architecture, development

J2EE Software Developer
J2EE Software Developer
Software architecture, development
  • Developed a highly customizable Billing System for TV-Commercials in context of AdManagement/ Sales System
  • Developed several Data Import/Export interfaces and tools
  • Developed several Data Migration PL/SQL Scripts
  • Developed several Report Data Collectors
S4M - Solution for Media GmbH
Cologne (Germany)
10 Monate
2004-10 - 2005-07

Software development

.NET Software Developer (working student)
.NET Software Developer (working student)
  • Implemented a Industry Roboter Controlling Application on Windows Embedded CE device
mz robolab GmbH
Rheinbach (Germany)
5 Monate
2002-10 - 2003-02

Software development

.NET Software Developer (working student)
.NET Software Developer (working student)
  • Implemented a Sync Web Tool to German Insurance Association (GDV)
Ineas Versicherung GmbH
Cologne (Germany)

Aus- und Weiterbildung

Aus- und Weiterbildung

2000 - 2005
Study - Allgemeine Informatik
Fachhochschule Köln/ Campus Gummersbach
Focus areas: Software Development and Artificial Intelligence (Artificial Neural Networks)
Degree: Diplom

Position

Position

Senior Software Engineer

Kompetenzen

Kompetenzen

Top-Skills

Java Spring SQL Maven Hibernate GWT PostgreSQL Spring Boot JEE Jenkins PL/SQL Git Java Swing Docker Vaadin MySQL Scrum JSF Oracle Dart PrimeFaces JavaScript Python

Produkte / Standards / Erfahrungen / Methoden

PROFILE
The candidate has been developing software for diverse companies and industries. While studying informatics he worked for an insurance company and for an industry roboter company. After his graduation and his prize-winning thesis in AI context he worked for a media corporation, a natural gas industry IT service contractor, a telecommunication company, an insurance company and a FinTech contractor. Since March 2019, he is working as a freelancer and supports his customers as a full-stack senior software engineer. He is team-minded and reliable with a strong focus to deliver high-quality results.

TECHNICAL SKILLS
Java, SQL, PL/SQL, JavaScript, Groovy, C#, PHP, Python, (Dart, Ruby, Go), Spring, Spring Boot, Spring Batch, JEE, JPA, Hibernate, Toplink/EclipseLink, PHP Symfony, JMS, REST, SOAP WebServices, TIBCO ESB, Quarkus, Vert.x, Android, JSF/PrimeFaces, Vue.js, Ember.js, GWT, JSP, Struts, Swing, Java-Applets, HTML, CSS, Polymer-JS, Angular.js, Vaadin, ActionScript/Flex, Elasticsearch, Oracle DB, MySQL/MariaDB, PostgreSQL, Sybase, MS SQL Server, H2, SQLite, Redis, Tomcat, JBoss, Glassfish, Oracle WebLogic, Maven, Ant, Gradle, Git, Subversion, Jenkins, Docker, OpenAPI/Swagger, JUnit, Selenium, Mockito, JMeter, MapStruct, IntelliJ IDEA, Eclipse, Android Studio, VS Code, Google Maps on Android, HERE Maps on Android, Highcharts-JS, WebRTC

Programmiersprachen

Java
JavaScript
Oracle/SQL
PL / SQL
SQL

Datenbanken

MySQL
Oracle
PostgreSQL
H2

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