My References
Conception, architecture and development of a modern, AI-supported corporate website. The project comprises a complete full-stack implementation with an integrated RAG-based (retrieval-augmented gener…
12/2025 -03/2026
Senior software developer and software architectMatthias Baumann Softwareentwicklungmore â–¾Projekt
Conception, architecture and development of a modern, AI-supported corporate website. The project comprises a complete full-stack implementation with an integrated RAG-based (retrieval-augmented generation) chatbot for context-sensitive user interaction. The front end was implemented as a Next.js 16 app router application with React 19 and TypeScript. PayloadCMS 3 is used as the headless CMS, which provides content management for multilingual pages (German/English) via MongoDB using next-intl. The design was created with Tailwind CSS 4. Lexical (PayloadCMS plugin) is used for the rich text editor. The integrated chat interface uses React Markdown with streaming support for real-time display of AI responses. The RAG service was implemented as a Python/FastAPI backend with the Haystack 2 framework. User queries are vectorised via an OpenAI-compatible embedding API (intfloat-multilingual-e5-large) and stored in a Qdrant vector database. The retrieval results are passed to a self-hosted LLM (LocalAI), which generates context-related responses. Rate limiting and session management are handled by MongoDB. A Quarkus 3 microservice (Java 25) was developed as a web crawler to populate the vector database. This extracts text content from web pages asynchronously using jsoup and indexes it via the RAG service in Qdrant. The service is compiled as a GraalVM Native Image for minimal resource consumption. In addition, a bot probe service (also Quarkus/Java 25 Native Image) was developed for automated monitoring of bot availability. This simulates 19 different bots (Googlebot, Bingbot, social media crawlers, etc.) and detects blockages caused by WAF rules, CAPTCHAs or HTTP status codes. An integrated React dashboard visualises the results in real time. The entire infrastructure is orchestrated on a self-operated K3s cluster. BunkerWeb serves as a reverse proxy with integrated WAF and automatic ACME certificate management. Plausible Analytics is used for data protection-compliant website tracking. The CI/CD pipeline via GitLab CI automates build, Docker image creation, Helm deployment and smoke tests. Feature branches are automatically deployed to separate staging environments. During development, Claude Code (Anthropic) was used extensively as an AI-powered development tool. Claude Code assisted with architecture planning, code generation, code reviews, debugging, and the creation of tests and infrastructure configurations. This enabled a significant acceleration of the development process while maintaining high code quality. Quality assurance includes automated testing using Vitest (unit tests) and Playwright (E2E tests) as well as test containers for database integration. ClamAV is integrated for antivirus scanning of file uploads.
Software
TypeScript, JavaScript, React 19, Next.js 16, PayloadCMS 3, Tailwind CSS 4, next-intl, Lexical, react-markdown, Python, FastAPI, Haystack 2, Java 25, Quarkus 3, GraalVM Native Image, jsoup, MongoDB 8, Qdrant (Vektordatenbank), LocalAI, Docker, K3s, Helm, Traefik, BunkerWeb (WAF), GitLab CI/CD, Playwright, Vitest, Testcontainers, ClamAV, Plausible Analytics, Claude Code (Anthropic)
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Matthias Baumann Softwareentwicklung
International rollout and localization of the B2B cloud platform. Significant involvement in the technical redesign (following DDD principles) and migration of a large B2B platform,
01/2024-01/2026
Senior Software DeveloperHARTING Technology Groupmore â–¾Projekt
International rollout and localization of the B2B cloud platform. Significant involvement in the technical redesign (following DDD principles) and migration of a large B2B platform, transitioning the application from a legacy commerce system to a modern, containerized microservices architecture deployed on Azure. My primary leadership responsibility was the end-to-end design and implementation of the extended Contentful Headless CMS ecosystem. This included: - Leading the development of a custom application based on the Contentful App Framework (using React and Forma36) to manage the entire content translation workflow. - Integration of the existing Across Translation Management System into Contentful using protocols (XLIFF over FTP and SOAP). - Integration of Canto's Media Delivery Cloud for Digital Asset Management. I delivered full-stack solutions using TypeScript, React and Node.js, ensuring high quality through pair programming, pair reviews and advanced automated testing (Jest, Playwright, Storybook). Continuous Deployment was managed via Azure DevOps in an agile/Scrum environment.
Software
TypeScript, React, JavaScript, CSS, Across, Canto, Canto REST API, Contentful (CPA, CDA and CMA REST APIs), Contentful Extension and App Framework, Angular 18/20, Node 18/22, Webpack, Docker, Kubernetes, Azure DevOps, Elastic Search
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HARTING Technology Group
Transformation of an on-premises monolith to a cloud-native Self-Contained Systems (SCS) architecture. During a five-year engagement,
06/2018-06/2023
Senior Software Developer and Software ArchitectProject work at a market leader for components, systems, and solutions in the field of electrical engineering from North Rhine-Westphaliamore â–¾Projekt
Transformation of an on-premises monolith to a cloud-native Self-Contained Systems (SCS) architecture. During a five-year engagement, I was involved in the entire lifecycle of a company-specific content management platform based on the Headless CMS Contentful. This encompassed the initial design following DDD principles and implementation through to continuous further development, international rollout, and stabilization. Requirements analysis was carried out in close coordination with editorial stakeholders. The project used agile methods, starting with Scrum for initial development and later transitioning to Kanban for managing continuous improvement and stabilization. The system architecture is based on Microservices / Self-Contained Systems (SCS). These were deployed as Docker containers and operated in the AWS Cloud. - The platform provided not only content capture but also the publication website, which displayed the editorial content available in the CMS. - Server-Side Includes (SSI) were used to integrate additional website content (e.g., from ERP or PIM systems) and ensure seamless presentation. To optimize editorial processes and comply with international requirements, Contentful Extensions and Contentful Apps were developed: - To ensure global consistency, an integration with the Across translation tool was implemented. - For asset management, connectors to the Digital Asset Management (DAM) system Canto were implemented. - An SEO management system was created to ensure compliance with search engine requirements and uniqueness across the SCS systems. - Additionally, apps were developed to improve the editorial workflow (including a multi-stage approval process) and to validate content structures. - Data models were versioned in Git and deployed via the Contentful Management API. - Internal system communication (between SCS systems) was realized asynchronously via Kafka and synchronously via REST interfaces. Kafka was used to ensure robust content synchronization across all services. - External access was provided via nginx as a reverse proxy. Quality assurance included pair programming, pair reviews, and automated tests (using JUnit, Cucumber, Selenium, and Testcontainers). Continuous Deployment (multiple daily PROD deployments) was managed via GitLab pipelines.
Software
Java, Kotlin, SQL, TypeScript, CSS, HTML, UML, PlantUML, Kafka, Java 11-17, Spring Boot 2.x-3.x, React, Contentful, Thymeleaf, Cucumber, AWS, MongoDB, PostgreSQL, Selenium, SonarQube, Elastic Search, JIRA, Git, GitLab, Docker, IntelliJ IDEA
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Project work at a market leader for components, systems, and solutions in the field of electrical engineering from North Rhine-Westphalia
Interface design for machine connection to an MES. Integration of an MES (Manufacturing Execution System) into an extended production environment for individual card production.
09/2015-05/2018
Senior Software Developer and Software ArchitectFreelance work at a market-leading provider of ID document solutionsmore â–¾Projekt
Interface design for machine connection to an MES. Integration of an MES (Manufacturing Execution System) into an extended production environment for individual card production. Extension of the SOAP-based interface, documentation and communication with machine manufacturers and PLC programmers. Extension of the test application (created by me in 2009-2011) to support machine test engineers.
Software
Java, Java EE, Spring, Swing, Apache Tomcat, WildFly Application Server, Bamboo, Atlassian JIRA, IntelliJ, Enterprise Architect
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Freelance work at a market-leading provider of ID document solutions
IoT system for home automation. Designing, implementing and assembling an IoT solution based on a Raspberry Pi, later ESP32. A system for controlling and interacting with sensors and actuators.
12/2012-jetzt
Senior Software Developer and Software ArchitectSelf-developmentmore â–¾Projekt
IoT system for home automation. Designing, implementing and assembling an IoT solution based on a Raspberry Pi, later ESP32. A system for controlling and interacting with sensors and actuators.
Software
C, C++, Node.js, Ionic with Angular and Go, MQTT
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Self-development
Extension of the plain Java backend and creation of a new JEE application. Extension of the backend in the existing SOA environment. Setting up a build system with Maven and Jenkins.
09/2012-08/2015
Senior Software DeveloperProject work at a market leader for components, systems, and solutions in the field of electrical engineering, electronics, and automation from North Rhine-Westphaliamore â–¾Projekt
Extension of the plain Java backend and creation of a new JEE application. Extension of the backend in the existing SOA environment. Setting up a build system with Maven and Jenkins. Creating a new application based on JEE (backend EJB 3.1 / REST WebServices) as well as Spring (MVC) and Portlet 2.0 (frontend).
Software
JAVA 1.6/1.7/JEE 6, Selenium, Maven 3, Jenkins, SonarQube, JIRA, SVN, Tomcat/TomEE 1.6/1.7, WebSphere Portal Server, Pluto, Eclipse 4.x, IntelliJ, SQL, Oracle
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Project work at a market leader for components, systems, and solutions in the field of electrical engineering, electronics, and automation from North Rhine-Westphalia
Connection of an MDE (Mobile Data Capture Device) to a backend system. Design and establishment of a build and dependency infrastructure with Maven and Quickbuild.
11/2011-07/2012
Senior Software DeveloperFreelancing for RIS (Rewe Informations Systeme GmbH), Colognemore â–¾Projekt
Connection of an MDE (Mobile Data Capture Device) to a backend system. Design and establishment of a build and dependency infrastructure with Maven and Quickbuild. Implementation of complex business logic in a three-tier architecture (REST web service, EJB/business layer and database).
Software
Java, Maven, Bamboo, DB/2, Eclipse, JBoss Application Server
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Freelancing for RIS (Rewe Informations Systeme GmbH), Cologne
Design and implementation of a JEE application in a SOA environment. Integration of a workflow engine for controlling printing machines.
06/2009-10/2011
Senior Software DeveloperFreelance work at a market-leading provider of ID document solutionsmore â–¾Projekt
Design and implementation of a JEE application in a SOA environment. Integration of a workflow engine for controlling printing machines. Integration of an MES (Manufacturing Execution System) into a newly established production environment for individual card production. Design of a SOAP-based interface, documentation and communication with machine manufacturers and PLC programmers. Design and development of a test application with a GUI (Java-SWING) to support machine test engineers. Design and implementation of a simulator in a SOA environment with integrated monitoring via a web application. The application simulates a subsection of an MES used in the real system. In the initial phase, production was partly carried out only with these simulators, as the target system was not yet operational.
Software
Java, Spring, Swing, SOAP, SoapUI, Oracle, WebLogic, Maven, Gradle, Bamboo, Enterprise Architect
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Freelance work at a market-leading provider of ID document solutions
Migration of an enterprise application. Migration of an enterprise application from BEA Weblogic 9.3 to IBM Websphere 6.1. Migration and extension of the SWT-based client application.
03/2009-05/2009
Software DeveloperFreelance work at a market-leading provider of ID document solutionsmore â–¾Projekt
Migration of an enterprise application. Migration of an enterprise application from BEA Weblogic 9.3 to IBM Websphere 6.1. Migration and extension of the SWT-based client application.
Software
Java, HTML, CSS, JSP, SOAP, Oracle, Maven, WebSphere Application Server, WebLogic
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Freelance work at a market-leading provider of ID document solutions
Development in the ECM area. Further development of an application based on Documentum 5.3 (webtop). Migration of the application to EMC Documentum 6.0 and subsequently to 6.5.
03/2008-02/2009
Software DeveloperFreelancing for automotive corporationmore â–¾Projekt
Development in the ECM area. Further development of an application based on Documentum 5.3 (webtop). Migration of the application to EMC Documentum 6.0 and subsequently to 6.5. Introduction of test automation with JMeter. Requirements analysis, design and implementation of a WebService (SOAP) interface to the DMS based on Documentum 6.5.
Software
Java, JSP, HTML, CSS, XML, Documentum, Apache Tomcat, DMS (EMC-Documentum 5.3/6.0/6.5), XSL, SQL, DQL, JavaScript, WDK, DFC, DFS, BEA Weblogic, JBoss, Tomcat, SUN Solaris 10, Oracle 10g, IBM WebSEAL, Eclipse, SVN, DqMan, JMeter, VMWare, Virtualbox
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Freelancing for automotive corporation
Further development of an existing Cocoon-based web application with extended configuration options (web application framework for the B2B platform of an automotive corporation). 1.
03/2002-02/2008
Software DeveloperWebware-Experts OHG for automotive corporation, Wolfsburgmore â–¾Projekt
Further development of an existing Cocoon-based web application with extended configuration options (web application framework for the B2B platform of an automotive corporation). 1. Software architecture and development of server applications based on J2EE within a SOA environment. Design and implementation of a search engine based on Lucene (apache.org). JCA connectors for connecting the Lucene search engine to a J2EE application. Configuration interface for connection configuration of the search engine to different backend systems. 2. Software architecture and development of server applications based on J2EE within a SOA environment. A SOA environment was implemented for communication between host systems and other legacy systems and a B2B portal. Communication between the involved systems took place across multiple firewalls (network zones). Design and implementation of an XML-driven persistence layer with JEE SessionBean. The focus was on the generality of the interface. 3. Further development of an existing Cocoon-based web application with extended configuration options. With interfaces to workflow, validation, and DMS systems. Communication between the involved systems took place across multiple firewalls (network zones). Performance analysis with JProfiler. Test automation with JMeter. Migration of existing J2EE applications from JAVA SUN 1.3.x under Solaris to 64 Bit IBM VM 1.4.x under RedHat on PSeries.
Software
JAVA, J2EE, MDB, SQL, XML, XSL, HTML, CSS, JavaScript, Cocoon, IBM Websphere 5.x/6.x, IBM MQSeries, IBM WebSEAL, Oracle 9i/10g, SUN Solaris, RedHat on pSeries, ANT, IVY, Eclipse, JMeter, JProfiler, Lucene
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Webware-Experts OHG for automotive corporation, Wolfsburg
Design and implementation of an xsd2xsd mapping tool based on XUL (XML User Interface Language by Mozilla).
04/2003-12/2007
Software DeveloperWebware-Experts OHGmore â–¾Projekt
Design and implementation of an xsd2xsd mapping tool based on XUL (XML User Interface Language by Mozilla).
Software
JavaScript, XUL, RDF, HTML, CSS, Eclipse, Java, Apache2, Cocoon, XSLT, CVS, ANT, Axis2, SOAP, MySQL 3.x/4.x
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Webware-Experts OHG
Redesign of an existing server application. Architectural redesign of a monolithic B2B platform (JAVA/DAO).
04/2001-02/2002
Software DeveloperWebware-Experts GbR for automotive corporation, Wolfsburgmore â–¾Projekt
Redesign of an existing server application. Architectural redesign of a monolithic B2B platform (JAVA/DAO). The existing application (web application of an automotive corporation) was transitioned from a monolithic structure to the MVC pattern. My core task was the design and implementation of an XML interface to the existing Java object model.
Software
Java, XML, HTML, JSP, SQL, Oracle
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Webware-Experts GbR for automotive corporation, Wolfsburg
Development of an order management software for the event industry. Application development (MS-Access 2.0/97/2000) for commercial and logistics processes. The application supported order management,
02/1998-02/2001
Software Developer at Compumedia GmbHCompumedia GmbH, Berlinmore â–¾Projekt
Development of an order management software for the event industry. Application development (MS-Access 2.0/97/2000) for commercial and logistics processes. The application supported order management, warehouse management and finance, including invoice creation and posting of incoming documents. Additionally, C implementation for controlling and direct database connection of wireless hand scanners (Formula 734F / Wizard).
Software
MS-Windows NT, Delphi 4.0, MS Access, MS SQL Server 7.0
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Compumedia GmbH, Berlin
Development of generalization algorithms for GIS and implementation of a prototype. This included the specification of generalization tasks, the development and implementation of the algorithms,
01/1996-01/1997
Self-employed Software DeveloperGeoResearch Institute Potsdammore â–¾Projekt
Development of generalization algorithms for GIS and implementation of a prototype. This included the specification of generalization tasks, the development and implementation of the algorithms, as well as the design and implementation of a test application for validating the results.
Software
MS-Windows NT, Delphi 2.0
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GeoResearch Institute Potsdam