Certified Kubernetes Application Developer

The goal of the project is to integrate a new document creation system (MText) into the existing system landscape. For this, I independently develop several Spring Boot microservices that handle the conversion from XML to JSON formats and control direct communication with MText. The applications are containerized and run in the AWS Cloud with Kubernetes and Helm.

• Developed an integration service that bundles multiple calls and acts as a facade for communicating with various services
• Developed a conversion service to transform unstructured XML files into structured JSON files for different business units
• Extensive unit and integration tests for file conversion; mocking interfaces with WireMock, Aspects, etc.
• Unified exception handling with @ControllerAdvice and Aspects
• Professional design of OAS definitions (design-first approach)
• Created client and server implementations based on OAS definitions (OpenAPI Specification) using code generators and managed them in Nexus
• Logging in combination with the ELK stack
• Integrated the MText server via HTTP calls
• Created DORA-compliant tests with Xray in coordination with testers
• Set up the CI/CD pipeline with GitLab Actions
• Handled security issues from AquaScan and coding issues from SonarQube
• Distributed services across different stages (Dev, Test, VProd, Prod)
• Set up and maintained Helm charts

Technologies used:

• Backend: Spring Boot, Java 17, JUnit5, OpenAPI (OAS), OAuth2, WireMock
• DevOps: GitLab CI/CD, Kubernetes, Docker, Anypoint, Nexus
• Cloud: AWS, EKS
• Project management: Jira, Confluence

The certification of large solar plants in Germany poses a challenge for many companies. Authorities require a lot of information, which companies have to collect in tedious processes. CarbonFreed offers an AI-supported platform where all stakeholders can enter, review, and jointly evaluate the information.

• Extensive automated Cypress tests
• Integrated tests into GitHub Actions
• Fixed minor frontend issues
• Managed master data with MongoDB
• Extensive Postman tests
• Integrated Postman tests into GitHub Actions
• Managed CI/CD pipelines with GitHub Actions
• Built cloud IT infrastructure in Azure (Terraform, AKS, ELK stack)

Technologies used:

• Frontend: Angular, Angular Material, Cypress
• Backend: ASP.NET Core, Entity Framework Core, MongoDB
• DevOps: GitHub Actions, automated tests (Cypress, Postman, Unit Tests)
• Cloud: Azure, AKS, Terraform, ELK stack
• Project management: Jira, Confluence, GitHub, Scrum

Siemens Energy Compressors GmbH is a manufacturer of large compressors. Each compressor is a custom build and consists of several hundred parts. Inventory management of these parts is handled with SAP. This system stores which parts belong to which machine, when they are delivered, or if they are still in stock. Unfortunately, the current SAP version does not offer extensive features to quickly and efficiently locate missing parts. Therefore, I developed a web interface that imports current machines from SAP, processes the data, stores it in a database, displays the necessary information in a user interface, and exports to Excel when needed. Data import is done via a CSV file exported from SAP.

• Made technology and architecture decisions
• ASP.NET Core: parsed the CSV file and stored the data in PostgreSQL
• Spring Boot: parts management with Hibernate and PostgreSQL
• Visualized and edited parts
• Search mask
• Import and export functions
• Built the cloud IT infrastructure
• Set up the CI/CD pipeline
• Gathered, documented, and prioritized requirements

Technologies used:

• Frontend: Angular, Angular Material
• Backend: ASP.NET Core, Entity Framework Core, Spring Boot, Hibernate, JPA
• DevOps: GitLab pipelines, GitLab Container Registry
• Cloud: Okteko Cloud, Kubernetes, Docker, Helm
• Project management: Kanban, Azure Boards, Azure Repos

As part of the digitalization process, parts of Euroglas GmbH's in-house IT infrastructure were adapted to modern technologies. Based on that, various modules were developed in the next step. One of these modules is a maintenance planner. It serves as an assistant system for maintenance to manage the servicing of hundreds of machines efficiently.

• Writing technical user stories
• Making technology decisions and implementing them
• Managing maintenance orders and machines
• Importing data from the old maintenance planner
• Frameworks: MSSQL, Entity Framework Core, Azure Directory
• Managing maintenance orders and their machines
• Assigning tasks to different employees
• Different views (maintenance planner and employees)
• Frameworks: NgRx, RxJS, Angular Material
• Setting up ASP.NET Core Identity for user management
• Integrating users from the internal Azure Active Directory
• Setting up and editing CI/CD pipelines with Azure DevOps Server and IIS
• Automated database migration
• Gathering, prioritizing, and documenting requirements from various sources (interviews, legacy software)

Technologies used:

• Frontend: Angular, Angular Material, NgRx, RxJS, HTML, CSS, TypeScript
• Backend: ASP.NET Core, Entity Framework Core, MSSQL
• DevOps: IIS, Azure Pipelines
• Project management: Azure Boards, Confluence, Bitbucket, Scrum

For Polarith UG, a plugin for the Unity Asset Store was developed to help customers create autonomously moving AI agents without programming skills. During development, a well-thought-out software design, a professional API documentation with Doxygen, and the application's performance were the main focus.

• C#
• .NET
• Unity
• Scrum
• CI
• Git
• Doxygen