Timo Rohrberg
Expert Software Developer
Experience
Expert Software Developer
HORNBACH Baumarkt AG
Maintain and extend the existing software
Plan and implement new features in the existing software
Support the operation of the existing software in the cloud
Java SE, Spring Boot, IntelliJ IDEA
Google Cloud, Kubernetes, Docker, Apache Kafka
IT Trainer
BREDEX GmbH
Create training materials
Design smaller exercises
Design larger, project-like exercises
Properly prepare the training content to be delivered
Deliver the provided training content
Facilitate individual and group work
Organize and provide technical support for individual and group work
Prepare and conduct small group or one-on-one trainings
Properly follow up after training, including correcting assignments
Java SE, Spring Boot, Docker, IntelliJ IDEA
Expert Software Developer
GROPYUS Technologies GmbH
Design and implement a new microservice
Implement parameterization based on a rules engine
Deploy the new microservice in Microsoft Azure
Document the design and implementation
Java SE, Kotlin, Spring Boot, IntelliJ IDEA
JBoss Drools, JBoss OptaPlanner, Microsoft Azure, Kubernetes, Docker
Consultant
Hellmann Worldwide Logistics SE & Co. KG
Analyze the existing software architecture
Analyze agile project management practices
Advise on improving the software architecture
Advise on agile project management practices
Atlassian JIRA and Confluence, Miro, Microsoft Teams
Expert Software Developer
Media-Saturn IT Services GmbH
Maintain and extend the existing software
Plan and implement new features in the existing software
Support the operation of the existing software in Google Cloud
Develop an architectural vision for a partial redevelopment
Java SE, Kotlin, Spring Boot, IntelliJ IDEA
Google Cloud, Kubernetes, Docker, Apache Kafka, PostgreSQL, MongoDB
DevOps Consultant
Hellmann Worldwide Logistics SE & Co. KG
Analysis of the existing infrastructure regarding CI/CD
Analysis of requirements for a new CI/CD system
Development of a rough concept for a new CI/CD system
Planning and organizational support for the commissioning of the CI/CD system
Kubernetes (on prem), Docker
Atlassian JIRA and Confluence, Miro, Microsoft Teams
Expert Software Developer
Media-Saturn IT Services GmbH
Design and implementation of interfaces
Implementation of event-based processing using Kafka
Implementation of stable error handling
Deployment of microservices to Google Cloud
Documentation of the design and implementation
Java SE, Kotlin, IntelliJ IDEA
Google Cloud, Kubernetes, Docker, Apache Kafka, MongoDB
Koin, Arrow-Kt, Http4k, Jackson, Testcontainers
Expert Software Developer
compeople AG
Design and documentation of the code generator architecture
Design and documentation of a domain-specific language (DSL)
Implementation of the code generator based on Apache Freemarker
Consultation and support for the use of the developer tool
Java SE, Kotlin, IntelliJ IDEA, Spring Boot, Apache Freemarker
Apache Maven including custom plugins, Jenkins
Kubernetes, Docker, Microsoft Azure
Expert Software Developer
compeople AG
Design and documentation of the architecture for a new backend
Design and documentation of the public interfaces of the new backend
Implementation of microservices based on Spring Boot
Advising on software architecture and agile methodologies
Java SE, Kotlin, IntelliJ IDEA, Spring Boot, Oracle, PostgreSQL
Apache Maven including custom plugins, Jenkins
Kubernetes, Docker, Microsoft Azure
Senior Software Developer
compeople AG
Maintenance and further development of existing Spring Boot-based microservices
Design and development of new Spring Boot-based microservices
Requirements analysis considering the existing solution
Interim support for the Product Owner
Java SE, Kotlin, Eclipse IDE, IntelliJ IDEA, Spring Boot, MongoDB
Kafka (partial), Apache Maven, Jenkins, Kubernetes, Docker
Senior Software Developer
compeople AG
Maintenance of existing UI frameworks
Support for external application developers
Bug analysis and fixing for reported issues
Setup and maintenance of a new build system
Requirements analysis considering the existing solution
Design and implementation of a new solution
Coordinating the rollout of the new solution with users
Preparations and support for introducing new technologies and tools
Training colleagues on the technologies and tools used
Java SE, Groovy, Eclipse IDE
OSGi, Eclipse Equinox, Eclipse RCP, Eclipse Riena, Hivemind
Apache Maven, Eclipse Tycho, Jenkins
Senior Software Architect and Developer
vitasystems GmbH
Requirements analysis with product management
Designing a component-based 3-tier architecture
Presenting and discussing the architecture design
Researching and selecting suitable technologies
Estimating effort and planning implementation steps
Preparations and support for introducing new technologies and tools
Training colleagues on the technologies and tools used
Implementing the system
Verifying the implementation through automated tests
Building and maintaining the build infrastructure
Creating compliant documentation according to ISO 13485
Java SE, Eclipse IDE
OSGi, Eclipse Equinox, Eclipse EMF, Eclipse Xtend
Eclipse Jetty, JAX-RS & Jersey, REST-assured
Apache Maven, Eclipse Tycho, Jenkins, Apache JMeter
Eclipse Teneo, Hibernate, PostgreSQL
Acting Product Owner
vitasystems GmbH
Support for introducing and using Scrum
Maintaining the product backlog
Facilitating key Scrum ceremonies (e.g., Sprint Planning, Sprint Review)
Atlassian JIRA, Atlassian Confluence
Software Architect and Developer
vitasystems GmbH
Requirements analysis for a new HTTP-based communication protocol
Developing and specifying the HTTP-based communication protocol
Creating compliant (ISO 13485) documentation for the protocol
HTTP, REST
Software Architect and Developer
vitasystems GmbH
Requirements analysis with product management
Estimating effort and planning implementation steps
Implementing new features and fixing bugs
Creating compliant documentation according to ISO 13485
Verifying the implementation through manual tests
Java SE, Eclipse IDE, Eclipse RCP
Apache Struts, Apache Tomcat, Apache HTTPd, JBoss RESTEasy
Hibernate, PostgreSQL, Apache Ant, Jenkins
Software Architect and Developer
init AG / initplan GmbH
Requirements analysis in collaboration with software development colleagues
Specifying an API based on collected requirements
Researching and selecting suitable technologies and tools
Designing the architecture and defining the API
Implementing parts of the API components
Java SE
SOAP & Webservices, Apache HTTPd, Apache Tomcat
Apache Maven, SparxSystems Enterprise Architect
Software Architect and Developer
init AG / initplan GmbH
Identifying weaknesses in the existing CI/build system
Requirements analysis in collaboration with software development colleagues
Researching and selecting suitable technologies and tools
Setting up and commissioning a central build server
Developing processes for planning and creating releases
Apache Maven, Apache Ant, Eclipse Tycho
Jenkins, JFrog Artifactory, Sonatype Nexus
Software Architect and Developer
init AG / initplan GmbH
Requirements analysis for a web client together with support and sales
Researching and selecting suitable technologies and tools
Designing the architecture of the web client and the interface to the legacy system
Implementing the web client
Java SE, Eclipse IDE
Java Servlets, JavaScript, jQuery & jQuery Mobile
Eclipse Jetty, Apache HTTPd, Apache Tomcat
Software Architect and Developer
init AG / initplan GmbH
Identifying and documenting weaknesses in the existing system
Requirements analysis for a new version together with support and sales
Designing a 3-tier architecture using proven architectural patterns
Presenting and discussing the architecture design
Estimating effort and planning implementation steps
Implementing the system while leading a team of three developers
Designing and implementing the build infrastructure with Maven/Tycho
Java SE, Eclipse IDE
Eclipse RCP/RAP, Eclipse SWT, Eclipse Jetty
Apache Maven, Eclipse Tycho, Jenkins
Versant Object Database, SparxSystems Enterprise Architect
Software Developer (Intern)
Módula Software Ltda.
Fixing implementation errors in the existing system
Implementing new features on all architecture layers of the system
Requirements analysis for a project management tool
Designing the architecture for this tool based on the main system architecture
Implementing the tool using existing libraries
Maintaining and further developing the build system based on DAnt
Borland Delphi
DAnt (Delphi version of Ant)
PostgreSQL
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 (9.5 years), Transportation (4.5 years), Healthcare (3 years), and Retail (1 year).
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 (13.5 years), Product Development (12.5 years), Quality Assurance (3 years), Project Management (2 years), and Operations (0.5 years).
Summary
More than thirteen years of professional experience in software development with Java and Kotlin.
A committed supporter of the Clean Code and Software Craftsmanship movement.
Focus areas include backend systems with event-driven architecture based on microservices implemented in Java and Kotlin, as well as component-based and model-driven software development with Eclipse Equinox (OSGi) and EMF.
Also extensive knowledge in build management, continuous integration, and release management.
Professional and personal experience abroad.
Skills
Programming Languages: Java, Kotlin, Javascript, Delphi, C++/c#, Groovy, Php, Perl, Python
Frameworks: Eclipse Equinox, Eclipse Emf, Eclipse Rcp/rap, Hibernate, Spring Boot
Databases: Postgresql, Oracle, Mysql, Mongodb, Microsoft Access, Versant Object Db
Data Communication: Rest, Soap, Rpc, Http, Tcp/ip, Kafka
Operating Systems / Platforms: Windows, Linux, Macos, Kubernetes, Gcp, Azure, Docker
Tools: Eclipse, Intellij, Postman, Soapui, Git, Subversion, Jira, Confluence
Methods: Scrum, Kanban
Languages
Education
Karlsruhe Institute of Technology (KIT)
Diploma in Computer Science · Diploma in Computer Science · Karlsruhe, Germany · 1.3
Certifications & licenses
iSAQB Certified Professional for Software Architecture (Foundation Level)
Certification as a medical device consultant according to §31 MPG
Profile
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