Portainer Experts in Germany

• Ride-sharing and bus platform, live and working. Backend Spring Boot 4.1 on Java 21, PostgreSQL with Flyway, Testcontainers integration tests. Running in my own AWS account (ECS Fargate, ALB, ECR, IAM least privilege) with CI/CD via GitHub Actions and OIDC federation without static credentials. Development throughout AI-assisted with Claude Code, including my own skills and project-specific memory. Spring Boot · Java 21 · PostgreSQL · Flyway · Docker · AWS ECS/ALB/ECR · CI/CD · GitHub Actions · Claude Code

Enhancement and modernization of a mature Aspire backend application in the environment of a utility company, focusing on new business requirements, testing, legacy code cleanup, and stable backend delivery.

Core contributions & results Implemented new business requirements in the context of customer orders, subcontractors, and cross-company backend processes, and ensured consistent workflows in a distributed system landscape. Modernized existing backend components step by step and reduced technical debt through targeted legacy code cleanup, refactoring, and structured code reviews. Improved the testability of business-critical services by expanding automated tests with xUnit, AutoFixture, and clearer validation structures. Supported the further development of workflow automations and integration processes via microservices, messaging, and API-based communication. Took over source code from external firms, systematically checked code quality, and derived technical improvements for maintainability, stability, and integration. Worked in agile development processes with Jira, Confluence, and Azure DevOps and supported cross-team alignment on architecture, quality, and implementation. Technical metrics Technologies & methods C#, .NET, ASP.NET, ASP.NET Core, Aspire, Docker, RabbitMQ, gRPC, REST API, Swagger, Microservices, NServiceBus, AutoMapper, Autofac, xUnit, AutoFixture, FluentValidation, Entity Framework Core, MediatR, Redis, Consul, Serilog, SonarQube, Azure DevOps, Azure Monitor, GitLab, Google Protocol Buffers, IronPDF, Mailjet, Jira, Confluence, Miro, agile development, Scrum, code reviews, refactoring, legacy code cleanup, workflow automation, power grids

• Building an AI & Data Consultancy Practice with the goal of helping European companies adopt Artificial Intelligence and modern data platforms
• End-to-end further development of a production system using modified coding agents (OpenCode). Tech stack: Kubernetes, Argo, Keycloak, Typescript, Grafana, GitOps, DevOps, Playwright
• Internal research project on the use of coding agents in the field of mathematical logic for creating formal models. Use of Cursor IDE and Codex, Codex CLI. Architecture design, quality control and refactoring, as well as writing code and tests. Repository (open source) available pre-launch
• Research on the role of mathematical logic as a formal language that connects IT and AI with business processes
• Project lead for collecting and deploying parking recommendations for rail vehicles with significant savings potential based on real-time data in a mobility and transport company
• Project lead for collecting and distributing process measurement points for real-time control in a mobility and transport company
• Deputy application owner for an app used for communication in the dispatching and provision of rail vehicles

• Technical leadership and architecture for enterprise clients (including LR Health & Beauty, Deutsche Bahn, Trusted Shops)
• Cloud migration, microservices architectures, CI/CD optimization

• CHG Meridian AG is a financial company focused on leasing in the areas of IT technology, logistics and medical technology and is regulated by BaFin. One part of the company is Return to Remarketing, where devices delivered to the technology center (notebooks, smartphones, tablets, etc.) are prepared for resale. The project I supported was responsible for enabling damage assessment of returned lease devices, documenting them visually in the form of pictures, enabling invoicing for the customer, and making the pictures available via the in-house customer platform. This was achieved through a combination of in-house development within the internal development department and the use of SaaS products. The second project was the transition of SaaS tendering software, purchased by the business unit, into the operations of the CHG IT department. Evaluation of security questions in relation to BaFin requirements, development of an authorization concept, implementation of single sign-on, documentation of the application in the CHG systems (CMDB, iKnow, etc.) and handover into operations.

Used technologies and methods: NIS2, DORA, agile software development, Scrum, Kanban, ServiceNow, SaaS, MS Teams, MS SharePoint, Active Directory, Entra ID, CMDB, incident management, change management, request management, service level agreement

• Analysis
• Consulting
• Software design
• Development
• Automation
• Testing
• Deployment
• Architecture, development and deployment of various proof-of-concept applications around the integration of current AI interfaces including conversational, realtime voice, images and videos
• Developed best practices for working with agentic systems and AI in practice
• Created code templates

• Architecture and implementation of a fully digitalized closing flow for managing securities contracts within the DVAG infrastructure. The platform aims for maximum user-friendliness, modular extensibility and compliant handling of sensitive data.

• Implementation of a reactive UI structure with a focus on user guidance & accessibility.

• Dynamic control of form and closing processes including validation logic.

• Reactive state management via SignalStore (signals + selective effects).

• UX optimization through adaptive components and Playwright-based UI tests.

• Backend modularization to connect existing sales and contract logic.

• API stability and DTO design according to Clean Architecture principles.

• Collaboration with domain teams to define technical contracts and service boundaries.

• Management with GitHub.

• Unit tests with Jest, E2E tests with Playwright.

• Code reviews, CI-integrated test execution, iterative refactorings.

• Ensuring high coverage and UI stability in the closing flow.

• Technologies: Angular 18, RxJS, SignalStore, HTML5, SCSS, Spring Boot, Kotlin, REST, OAuth2, Jest, Playwright, Clean Architecture.

• Development of a plug-and-play solution for game server operators to collect, process, and display game server data
• Integration of a subscription-based payment system
• Technologies: C#-10, .NET5, SQL, .NET8, PostgreSQL, Angular, JavaScript, TypeScript, CSS, Entity Framework, TailwindCSS, OIDC, JWT, Stripe, OAuth2.0, Docker, Testing, Portainer, PowerShell

• Overall technical responsibility for innovative SAP Customer Checkout solutions at leading clients such as Aramark, Consortium Gastronomie, Feinkost Käfer, TSG Hoffenheim, and VfB Stuttgart. Full support from requirements analysis to implementation and support.

• Successful conception and development of the NDS SmartPOS platform ("Läufer App"):

• Designed the software architecture and implemented it according to Modern Android Development principles.

• Led a small development team (1 Android expert, 1 working student) with a 50% in-house development share.

• Integrated various payment SDKs (S-Payment S-POS, VR Payment, CCV), enabling clients to achieve significant cost savings by reusing existing contracts.

• Successfully rolled out to multiple major clients, resulting in demonstrably increased efficiency of sales staff.

• Independently developed and successfully implemented critical infrastructure components:

• Reporting server (SQL, JasperReports): Measurable reduction in accounting effort by eliminating daily manual transfers into the ERP system.

• ZVT plugin: Solely implemented the serial protocol with Java/Netty over TCP/IP, saving several thousand euros per location and successfully deployed in multiple Bundesliga stadiums.

• Completely in-house development of specialized plugins and server applications for custom functionality extensions of SAP Customer Checkout:

• Waiter Teams Plugin: Allows waiters to work and settle bills in teams.

• SQL reporting: Realized from conception to full documentation independently.

• RFID payment solution for employee cards: Responsible for the complete development cycle.

• Integration with reservation services: Designed seamless connections to Luca and other services, implemented together with a team member.

• Direct technical on-site support for clients, including rapid troubleshooting in real-time environments with high transaction volumes and close coordination with stakeholders to continuously improve the systems based on practical experience.

• Fixing issues in the application logic

• Covering the changes with component tests

• Analyzing and documenting the data structure of the different applications

• Analyzing and documenting the parameters for configuring the applications

• Analyzing and documenting the necessary measures to ensure the operation of the applications

• Analyzing and designing the separation of the individual database structures

• Analyzing and estimating the effort for planned enhancements

• Analysis, maintenance and documentation of a heterogeneous legacy system landscape for a print media service provider

• Technology: C#, VB.NET, C, Python, Microsoft SQL Server, Visual Studio 2010, JetBrains Rider, Visual Studio Code, arc42, Draw.io, Jira, GitLab

• Software design & development (external and internal projects)
• Product management
• System and software architecture
• Purchase, sales, marketing
• Software project management
• Thematic focus: Video streaming, image & signal processing, consumer electronics, medical applications, automotive HMI, learning systems

• Design and implementation of a solution for managing projects, materials, and assets in field operations
• Development of a modern web application (Blazor) for project managers to track inventory, plan demand, and issue transport and purchase orders
• Delivery of a mobile MAUI app for field staff to store and retrieve materials with location-based photo documentation in map views
• Control of the full business logic through a central API
• Tech stack: .NET 9, C#, WebAPI, Blazor, MAUI, REST, PostgreSQL, Entity Framework, Docker, Docker Compose, Ansible, Keycloak, Aspire
• Identity and access management with Keycloak
• Deployment and orchestration via Docker Compose and Ansible
• Project in testing and evaluation phase