Profile
Consulting - Conception - Implementation - Test
More than 18 years of project experience in small, medium-sized and large software projects, working as a freelancer since 2011. Focus: full stack development with Java, Kotlin, Spring and React – from architecture and implementation through to test automation and continuous deployment.
Below you will find an overview of focus areas, skills and project references.
Focus Areas
Backend and Architecture
Java, Kotlin, Spring Boot, microservices, hexagonal architectures, CQRS, event sourcing, domain-driven design
Frontend
React, Angular, TypeScript – from component design to end-to-end test automation
Cloud and Operations
AWS, Kubernetes, Docker, Terraform, ArgoCD – including CI/CD pipelines and monitoring
Security and Identity
Keycloak including custom SPIs and auth flows, OAuth2, OIDC, single sign-on, AWS Cognito
Quality and Test Automation
TDD, BDD, Testcontainers, Playwright, Cucumber, consumer-driven contract tests
AI-assisted Development
Claude Code, GitHub Copilot, AI agents, RAG and vector databases, AWS Bedrock
Skills
Programming Languages
Java, Kotlin, TypeScript, JavaScript, C#/.NET, C/C++, PHP, SQL, PL/SQL, Bash
Technologies and Frameworks
Spring Boot, Spring Security, Spring Data, Spring MVC, JPA, Hibernate, REST, SOAP, Lucene, Elasticsearch, JavaFX, Jakarta EE
Architecture and Methods
Microservices, hexagonal architectures, CQRS, event sourcing, domain-driven design, design patterns, Scrum, Kanban, pair programming
Quality and Test
TDD, BDD, JUnit, Mockito, Testcontainers, Playwright, Cucumber, Pact, SonarQube, JaCoCo, end-to-end and integration tests
Build and Continuous Deployment
Gradle, Maven, GitLab CI/CD, Jenkins pipelines, Concourse CI, Renovate, Dependabot, Git, GitHub, GitLab
Cloud and Infrastructure
AWS (EKS, ECS, Fargate, Lambda, SQS/SNS, Bedrock, Secrets Manager), Kubernetes, Docker, Terraform, ArgoCD, Kustomize
Databases and Messaging
PostgreSQL, Oracle DB, MS SQL Server, MySQL, MongoDB, H2, Kafka, AWS SQS/SNS, Liquibase, Flyway
Monitoring
Prometheus, Grafana, Datadog, Kibana and ELK stack, Spring Boot Admin, AKHQ
Operating Systems and Tools
Unix, Linux, macOS, Windows, IntelliJ IDEA, Rider, Nginx, Tomcat, Wildfly, JBoss
Project References
Clients are deliberately not named here. A detailed list of projects is available on request.
Overview:
Underwriting platform for assessing insurance applications
- Industry
- Reinsurance
- Client
- International reinsurance company
- Period
- since 09/2022
- Tasks
- Frontend and backend development, QA and test automation, CI/CD and deployment, documentation, coaching
- Technologies
- Java, Spring Boot, Angular, TypeScript, Lucene, PostgreSQL, MS SQL, Liquibase, Docker, Keycloak, OAuth2/OIDC, Cucumber, Playwright, Jenkins, AI agents and RAG
Microservices for the management of agricultural businesses
- Industry
- Agriculture
- Client
- Provider of an agricultural software platform
- Period
- 06/2021 - 09/2022
- Tasks
- Implementation of microservices for farm supplies, crop protection and fertilisers, machinery, people, crops, varieties and harvested goods
- Technologies
- Java, Spring Boot, TypeScript, React, Kafka, PostgreSQL, AWS (EKS, Fargate, CloudFormation), GitLab CI, Testcontainers, Pact, Cucumber, Prometheus, Grafana, Kibana
Chatbot engine for digital application processes in long-term care
- Industry
- Insurance / long-term care
- Client
- Digital provider in the care and insurance sector
- Period
- 09/2020 - 06/2021
- Tasks
- Conception, implementation and testing of a flexible chatbot engine for care application processes, onboarding of further insurers, deployment and release management
- Technologies
- Java, microservices, domain-driven design, JGraphT, React, React Native, Kubernetes, ArgoCD, Kustomize, Terraform, Kafka, AWS SNS/SQS, MongoDB, Keycloak, SSO, Datadog
Customer account and authentication system for a retail chain
- Industry
- Optical retail
- Client
- Retail chain in the optical industry
- Period
- 04/2019 - 09/2020
- Tasks
- Implementation of an SSO client library, development of Keycloak extensions and SPIs, application for customer administration, modularisation of components into self-contained systems
- Technologies
- Kotlin, Spring Boot, CQRS, event sourcing, Kafka, TypeScript, React, .NET/C#, Docker, Kubernetes, Keycloak, OAuth2/OIDC, AWS Cognito and Lambda, Elasticsearch, Concourse CI, SonarQube
Highly available B2B integration platform for internationally distributed teams
- Industry
- Logistics
- Client
- International logistics group
- Period
- 04/2017 - 03/2019
- Tasks
- Further development and new development of software systems and microservices in a heterogeneous system landscape
- Technologies
- Java, Spring Boot, Gradle, MongoDB, Docker, Ansible, Groovy, Vaadin, JavaFX, XSD/XSLT, Flyway, Liquibase, Jenkins pipelines, GitLab API, Nginx, Python, TDD and pair programming
E-commerce software for product data, shop search and marketplace integration
- Industry
- E-commerce
- Client
- Specialist retailer for toys and stationery
- Period
- since 2014
- Tasks
- Planning, implementation, testing and commissioning: simplified maintenance of product data, rule-based monitoring of on-page potential, integration of external marketplace interfaces, improved shop search through configurable synonym rules
- Technologies
- Java, Kotlin, Spring Boot, Spring Security, Spring Data, React, JavaFX, eBay API, REST, OAuth2, Keycloak, Docker, GitLab CI, Renovate, PHP
Self-service terminal software for vehicle rental
- Industry
- Automotive
- Client
- International car rental company
- Period
- 05/2016 - 08/2016
- Tasks
- Implementation of a JavaFX client, integration of REST services as well as a camera and a key safe
- Technologies
- Java 8, JavaFX, REST, JUnit, Mockito
Integrated information system for worldwide logistics processes
- Industry
- Shipping, logistics
- Client
- IT service provider of an international shipping company
- Period
- 06/2012 - 12/2016
- Tasks
- Implementation and testing of a system that replaces, modernises and standardises existing business and logistics processes worldwide
- Technologies
- Java EE, Glassfish, EclipseLink, CDI, JSF, Gradle, Jenkins, Oracle DB, JUnit, Mockito, SonarQube, Checkstyle, Git and Gerrit
Measuring device control for the evaluation and visualisation of optical filter curves
- Industry
- Optical glass, specialty glass
- Client
- Manufacturer of optical specialty glass
- Period
- 12/2011 - 04/2012
- Tasks
- Planning, conception, implementation, testing and commissioning: control of a spectrometer, comparison of ISO target and actual curves, display of limit ranges, PDF export of measurement results
- Technologies
- Java SE, Hibernate, Swing, JUnit, Apache POI, iText
Restructuring and optimisation of private loan application processes
- Industry
- Banking
- Client
- German private bank
- Period
- 04/2011 - 09/2011
- Tasks
- Analysis and modelling of business processes, model-driven implementation of operational processes using BPMN software
- Technologies
- Jakarta EE, EJB, JSF, MyFaces, Hibernate and Envers, Spring, BPMN, Oracle, JBoss, JAX-B, JUnit, UML
Alarm monitoring system for infusion pumps
- Industry
- Medical technology
- Client
- Manufacturer of medical technology
- Period
- 05/2009 - 04/2011
- Tasks
- Technical conception and realisation of a multithreaded embedded C/C++ application as well as Java web services for the transmission of infusion data; multilingual standard application for monitoring, reporting and configuration
- Technologies
- Java EE, EJB, Richfaces, GWT, JBoss, Oracle, SOAP web services, C/C++, CAN bus, Embedded Visual C++, Windows CE, UML and Enterprise Architect
Further Projects
- 2009
- Storage management system for a software manufacturer – design, programming and testing of components for storage management and file handling (Java, EJB, Spring, JBoss, Oracle)
- 2008
- Java client for securities reconciliation for a German securities house – design, implementation, testing and commissioning (Java, Swing, JDBC, MS SQL Server)
- 2008
- Online brokerage platform for a major German bank – implementation of features, creation of test plans, module and integration tests (Java, JSF, JUnit)
- 2004 - 2007
- Project information system, CMS and interfaces for a mobile network service provider – planning, conception, implementation and team leadership (Java EE, Struts, JSP, EJB, Informix, JBoss)
Industry Experience
Reinsurance · Insurance · Banking · Logistics and shipping · E-commerce · Agriculture · Medical technology · Optical retail · Telecommunications · Automotive · Software manufacturers · Optical and specialty glass
Career and Training
Professional Career
- since 2011
- Freelance full stack developer with a focus on backend
- 2008 - 2011
- Consultant and developer with a focus on Java at an IT service provider
- 2003 - 2007
- Cooperative degree programme in computer science, business informatics, Darmstadt University of Applied Sciences – Bachelor of Science
Certifications and Training
- 2011
- BPM developer training; business process modelling with BPMN
- 2010
- Java Server Faces; IT consultant communication training; conflict management
- 2009
- Hibernate and Java Persistence API; Oracle SQL
- 2008
- Java web services; JBoss administration; WebSphere Application Server; EJB programming; Unix and Linux fundamentals
Speaker on object-oriented programming, Java programming as well as Hibernate and JPA (2009 - 2011).
Languages
German
Native speaker
English
Business fluent
Spanish and French
Basic knowledge
Do you have a project that matches this profile? Get in touch.