Jakarta EE Experts in Munich

• 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

• Build and operate an end-to-end MLOps platform on Azure ML and Kubernetes (Kubeflow) for the automated deployment, monitoring, and scaling of forecasting models (including Temporal Fusion Transformer, Informer, Autoformer).
• Implement CI/CD pipelines in Azure DevOps for the full ML lifecycle – from resource provisioning (Terraform), data transformation (Hugging Face Datasets, Pandas, PyTorch, CUDA cluster) through training and evaluation to model registry and endpoint deployment.
• Integrate MLflow for experiment tracking, model versioning, performance monitoring, and automated registration in the Azure Model Registry.
• Develop and containerize PyTorch training jobs (Azure Notebook, Jupyter Notebooks) for price and time series forecasting (PFC models) with automatic rollout via Azure ML Endpoints and REST/gRPC interfaces, Docker containerization, secured with OAuth 2.0.
• Set up monitoring and alerting mechanisms (Prometheus, MLflow Metrics), log centralization, and cost monitoring.
• Automate infrastructure provisioning and model deployment using Terraform, Helm, and Azure CLI; connect to existing market data systems and event pipelines.
• Migrate existing workloads and databases (IONOS → Azure, MongoDB) with integration into central MLOps workflows and internal networks.
• Extend the platform with LLM-based tools (LangChain, LangServe) to integrate GPT-based analysis modules into existing Spring Boot services for market anomaly detection and automated reports.
• Analyze and architect a software solution to process large volumes of data efficiently (>3000 messages/sec.) (market data store).
• Spring Boot / Java 21 container development with RabbitMQ for distributing stock market data via MongoDB (Kubernetes) with fast storage of data in Redis RMaps, deduplication, forwarding messages to Read Model queues, and building Read Models for UI display in MongoDB.
• Integration of RESTHeart to create a REST API for MongoDB.
• Build an Angular frontend to simplify data queries and master data maintenance.
• Agentic coding with remote and local LLMs (Claude Sonnet, Ollama Qwen) and MCP servers.
• Develop Python scripts for transforming and cleaning incoming stock market data (Pandas, scikit-learn).

Conducted an independent technical assessment of an AI-enabled software platform, combining AI risk auditing, cybersecurity analysis and software architecture review. Reviewed application components, APIs, data flows, LLM integrations, retrieval-augmented generation, multi-agent orchestration, authentication, tenant isolation, dependency vulnerabilities, AI governance and model lifecycle controls. Authored a technical audit report with a structured risk register, source-code evidence, regulatory references, corrective actions, AI system inventory, risk classification, remediation roadmap and Key Risk Indicators.

Technologies: TypeScript, JavaScript, React, Next.js, Node.js, REST APIs, MongoDB, Redis, AWS serverless services, OAuth 2.0 / OpenID Connect, LLM APIs, RAG, vector search, multi-agent orchestration, Model Context Protocol, C4 architecture modelling, threat modelling, NIST AI RMF, ISO/IEC 42001, ISO/IEC 23894, OWASP guidance, MITRE ATLAS

• Responsible for Openshift/Kubernetes on-prem administration and developer support.
• Developed URP infrastructure automation with Python, Ansible, Kustomize and ArgoCD, Argo Workflow/Events stack.
• Wrote smoke and load tests for URP infrastructure utilizing Python, Kustomize and ApplicationSets.
• Helped to set up and deploy URP infrastructure in Google Cloud, GKE.
• Set up monitoring for URP and ArgoCD stack with Splunk Cloud.
• Performed system administration tasks across RedHat Linux, Kubernetes/Openshift, ArgoCD, GitLab, Bitbucket Enterprise, Kafka and MongoDB.

• 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

End Customer: Openry GmbH

E-commerce platform to globally commercialize high-quality Italian artistic productions. Several European shops are already operational and Asian markets soon coming up. My role as Agile Project Manager is to lead the complete team on both the customer and technical side (offshore) including strong strategic consulting, in a continuous delivery approach. As project in a small enterprise, the budget management aspects are particularly challenging, in a quest to deliver the maximum business value with minimal overheads. Technologies: Magento 2, M2E Pro, Linux, Apache, MySql, PHP (LAMP), Stripe

• Managing the project team for the rollout of an e-invoice solution in more than a dozen countries
• Carrying out the needs analysis as well as the analysis of the current status (technical, organizational, legal)
• Coordination with all country organizations
• Selection and implementation of the e-invoice tool
• Ensuring the project stays on time and on budget

• 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

• Business and technical consulting for master data provisioning and process management
• Support for transition management
• Process optimization
• Interface definition

• Fullstack development based on Next.js and TypeScript
• Development and optimization of geospatial database queries for PostgreSQL/PostGIS
• Visualization of geospatial data using Mapbox
• Design and execution of load tests and performance optimizations
• Code reviews and documentation tasks
• Technologies: JavaScript, TypeScript, Next.js, React, Zod, tRPC, Storybooks, PostgreSQL/PostGIS, MicroORM, Knex, Material UI, Mapbox, BullMQ, Jest, Playwright, Artillery.io, K6, Sentry, Figma, GitLab, Grafana, GTFS

• Set up the new digitization strategy.
• Using Camunda as a process engine, a new way of handling batch and dialog tasks is created.
• In close cooperation with the business department, the individual processes are created and put into production.
• Forms for controlling manual interventions, e.g. when adjusting applications, are implemented.
• Gradual migration of old code from IBM WebSphere to JBoss.
• Skills: Arquillian, Camunda, Initiative, Empathy, Hibernate, Jackson, Java/JEE, JBoss, Jersey, JSON, JUnit, Openness to criticism, Willingness to learn, REST, Teamwork, WebServices.

• Head of overall technical integration NSC (National Secure Cloud, project with approx. 60 employees).

• Technical integration of all subprojects into one product, definition of interfaces and basic components of a cloud including hardware, technical architecture of the IABG platform.

• Development of a Cloud Management Platform (CMP) capable of creating private/mixed clouds of any complexity based on a textual description with one click or interactively.

• CMP also includes the complete hardware management lifecycle.

• Kubernetes, OpenStack and Hadoop are used as the foundation.

• The management layer includes Harbor, Gitea, Longhorn, Keycloak, Rancher and Jenkins, which are configured automatically.

• Private cloud can run any customer workloads, including a full Hadoop layer with HDFS, Spark, MapReduce, Mesos, HBase and around 20 additional ML/DL technologies.

• Hadoop worker clusters can also be installed automatically without Kubernetes on bare metal or commodity hardware.

• OpenStack with Nova, Neutron, Ironic, Swift, Cinder, Ceph.

• Development of a Java application Rudi: SOAP, REST, containers, DB.

• Technologies: Kubernetes (K3s, Rke2, Minikube, Harbor, Gitea, Jenkins, Longhorn, Keycloak, Rancher), OpenStack (Nova, Neutron, Keystone, Swift, Ceph, Cinder, Sahara, Magnum, Kayobe, Kolla, Bigrost, Ironic), Hadoop (HDFS, Ambari, Solr, Livy, Ranger, YARN, Tez, HBase, Kafka, Hive, Zookeeper, MapReduce, Spark, Oozie, Flink), virtualization (Kubernetes (K3S), VMware, Oracle), scripting (Ansible, Puppet, Juju, Shell, Groovy, Gradle, Maven).