JUnit Experts in Munich

• Recurring problem in my own AI-assisted projects: requirements analysis, use cases, and architecture decisions can be created quickly with AI support, but remain difficult to follow and scattered across Markdown files – knowledge is lost as soon as it is no longer in the context window. arknet turns requirements engineering and architecture knowledge into structured, verifiable data instead of plain text: requirements, use cases, and architecture decisions form a consistently linked knowledge graph, traceable from requirement to architecture decision – queryable by both people and AI agents. Technically based on RDF/OWL and a custom MCP server.

• Result: Working MCP daemon, Docker image published automatically to GHCR, nine hexagonal modules, eleven ADRs (including an Open-Core licensing model). Requirements engineering and Ubiquitous Language hexagons are active. Public as a Community Edition under Apache-2.0 since 07/2026 (github.com/kogn-io/arknet), together with the Claude Code plugin and GHCR image; Open-Core model.

• Label: Java, Maven, RDF, RDF4J, OWL, SPARQL, Model Context Protocol, Spring AI, Docker, GitHub, Git, Claude Code, Obsidian, DDD, Hexagonal Architecture, ArchUnit, JUnit, AssertJ, Interface Development, Software Architecture, Continuous Integration, Knowledge Management

• Modernization of a large-scale Java enterprise application*

The project is modernizing a complex enterprise application that has grown over many years. The existing Spring-based legacy system runs on Java 8, OSGi, and Eclipse RCP and is being gradually migrated to a modern, maintainable architecture with Java 25 and Quarkus.

Marcus works on analysis, architecture, refactoring, and implementation. One focus is on untangling historically grown structures and dependencies and on building a clean, sustainable Java and Quarkus technology stack.

Tools & technologies: Java 8, Java 25, Quarkus, Hibernate ORM with Panache, EclipseLink, OSGi, Eclipse RCP, Maven, JUnit, Mockito, REST, JSON, Git, Eclipse IDE, IntelliJ IDEA Ultimate, Jira, Confluence

• Iterative test planning

• Provision of the test infrastructure

• Resource planning

• Test concept development

• Coordination of the test teams

• Defect management

• Release management

• Project planning

• Cohort planning

• Test planning

• Test execution

• Trial test planning

• Rollout

• Business analysis

• Requirements engineering

• Change management

• E2E test coordination

Oracle Project Management and Automation

As part of the project, the operation of an Oracle infrastructure was automated by developing and enhancing Puppet modules and migrating existing Bash scripts to a standardized configuration management solution.

The aim of the project was to standardize and automate administrative processes, improve the maintainability of the Oracle platform, and increase the efficiency and traceability of infrastructure management through the use of Infrastructure as Code.

• Analysis and migration of existing Bash shell scripts to a Puppet-based automation solution
• Development and enhancement of Puppet modules for Oracle environments
• Automation of installation, configuration and operational processes using Infrastructure as Code
• Standardization and optimization of configuration management for Oracle systems
• Creation and maintenance of technical and operational documentation
• Planning, coordination and professional support during project implementation
• Operation and automation of Oracle systems on x86-based Linux server platforms
• Testing and quality assurance of the developed Puppet modules
• Analysis and resolution of technical errors as part of the automation and migration
• Close coordination with specialist departments and infrastructure teams to implement automation requirements

Technologies used: Puppet 7/8, SLES 15, Oracle 19, Oracle Grid, SVN, Windows Server, Confluence, VS Code, Ruby, Bash, Pass

• Designing the audit logging framework
• Implementing APIs for developers to integrate in their codebase
• Implementing ingestion pipeline, database query layer and UI for browsing the audit events
• Improving stability and reliability of the backend system

• Spring Boot Software Engineer
• DevOps Engineer (Kubernetes, Azure DevOps)

Toolstack: Java, Spring Boot, Kubernetes, Helm, GitOps, ArgoCD, Docker, Azure DevOps, CI/CD Pipelines, Git, Postgres

• Development of the digital organ donation register, commissioned by the Federal Institute for Drugs and Medical Devices (BfArM)

• Implementation of user stories in several microservices (frontend and backend)

• Ensuring quality with unit, integration, and E2E tests

• Conducting code reviews

• Coordination with other development teams

• Taking over the software license check and simplifying the process

• Responsibility for implementing and documenting the business logging

• Setting up a development environment with Docker Compose

• Overall responsibility for the project lifecycle from scope definition to completion
• Close collaboration with platform teams, IT leaders, and external service providers
• Application of SAFe principles and structured sprint work
• Creation of a migration roadmap with clear milestones
• Monitoring of the lifecycle: onboarding, repository migration, replication of permissions, and system tests
• Visualization of the architecture with PlantUML and Gliffy as well as documentation in Confluence
• Regular status reports and running knowledge transfer sessions

• Overall responsibility for the quality of module KH
• Technical leadership and coordination of a module lead team
• Analysis of design models and alignment of technical requirements
• Preparation of risk analyses and presentations, and presenting them to decision-makers
• Test management, development, coordination and approval of current test cases and their prioritization for test events
• Test planning for different test phases
• Coordination of test phases with other departments to ensure relevant aspects of business operations
• Prioritization of handling existing bugs/tickets
• Tracking and validation of the quality of problem management
• Consistency checks, planning, prioritization and sorting of tickets
• Preparation and coordination of required test data
• Tracking ALM (QC) processes and their implementation at module level
• Collaboration with interface partners for bug fixes
• Ensuring effective communication within the team and with interface partners
• Coordination of tasks when processing tickets in ML KH
• Tracking, assignment and clarification of bug-fix scheduling
• Close collaboration and management of suppliers (at module level), the development department, and external partners
• Planning, development, execution and evaluation of functional tests
• Conducting functional end-to-end tests
• Weekly reports on current test and defect status to management committees
• Planning and executing performance and load tests to ensure that SOA applications meet expected performance and scalability requirements
• Developing test strategies and test plans for SOA-based applications
• Defining test objectives and criteria to ensure services meet requirements
• Integration of test automation

Project: Tax Exemption Order Application

The client has an existing application for creating and maintaining tax exemption orders for end customers; design and implementation of a comparable application for internal employees.

• Design and implementation of microservices and the UI for the business area "tax exemption orders" using Domain Driven Design as well as Spring Boot and Angular.
• Implementation of reactive, non-reactive, and asynchronous APIs (Spring REST, WebFlux, GraphQL).
• Development of the Angular application, including state management using Signals, RxJS Observables, and subscriptions.
• Securing the API and the application using OAuth2, JWT, and OpenID Connect.
• Configuration and setup of CI/CD pipelines with Jenkins.
• Collaboration with cross-functional teams and conducting code reviews.

Environment: Java, Spring Boot, Angular 18 & 19 (standalone, signals), RxJs, Bootstrap CSS, Vitesting, OpenShift, Istio, microservices, Kafka, Dynatrace, Jenkins, GitLab, Graylog, Sonar, Oauth2, OracleDB

• Implementation of a GitLab CI/CD pipeline based on SAP Commerce Cloud 2211
• Development of a new B2C shop with Vue, Node and TypeScript to ensure scalability, extensibility and performance optimization
• Integration of Microsoft Azure Event Grid with SAP Hybris
• Implementation of BDD with Cucumber using Gherkin syntax to promote collaboration between development and business teams
• Support and customization of a Spartacus shop
• Technologies/Languages: Java, REST, OData, Behavior Driven Development (BDD), Cucumber, Node, Vue, TypeScript, Spartacus, GitLab CI/CD, Gradle, Maven, Ant, SonarQube

• Designed and built from scratch the automation framework using Playwright, Typescript, JavaScript, Gherkin, Cucumber, BDD, Maven, IntelliJ IDEA
• Defined, developed and maintained test plans, test scripts, reports and other QA documentation in Confluence
• Created and maintained test data with SQL Server Management Studio, Toad and Faker.js
• Performed web services and API testing using Swagger Open API, SoapUI, JSON, HTML and XML
• Executed functional, smoke, regression, black box, GUI, cross-browser, UAT and E2E testing using CrossBrowserTesting and Safari Web Inspector
• Integrated and maintained automated scripts within sprints following Kanban, CI/CD, GitHub, Docker, Azure Pipelines, Agile, Scrum, Kafka and Kibana
• Raised and managed defects in Azure DevOps
• Conducted mobile testing with Robot Framework and Appium

• Participated in the gradual modernization of components into cloud-native 12-factor applications.
• Worked closely with the business operations team to eliminate manual processes and resolve several performance bottlenecks.
• Designed and implemented a CI/CD pipeline to increase developer productivity, enforce quality and security checks, and automate product delivery.
• Migrated several components into the OpenShift Kubernetes cluster.
• Built a monitoring stack from scratch with Prometheus and Grafana to monitor services running in OpenShift.
• Developed dashboards in both Grafana and Splunk for operational transparency.
• Implemented an OIDC/OAuth2-based single sign-on (SSO) solution with Keycloak to secure multiple applications.
• Technologies: Java, Spring, Quarkus, Kafka, MySQL, Cassandra, Redis, Spring Data, Hibernate, Docker, Kubernetes, OpenShift, Keycloak, OIDC, OAuth2, Helm, Prometheus, Grafana, Splunk, Spark.

• Backend development of B2B e-commerce solution using SAP Commerce Cloud, leveraging Java and Spring Framework with creation of REST APIs for effective communication.
• Resolved software defects, developed automated cron jobs and triggers, and authored unit tests with JUnit to uphold code stability and quality standards.
• Utilized Git-based version control systems (Bitbucket/GitHub) for source code management and used Jenkins to support continuous integration and development (CI/CD).
• Executed and closed multiple user stories and tickets across iterative bi-weekly sprints under Agile (SCRUM) methodology.
• Led incident resolution in the production environment and minimized downtime through real-time monitoring (Solr, SAP CCv2, OpenSearch Dashboards) and sustaining SLA targets above 99%.