Certified Kubernetes Application Developer

Project goal was to integrate a new document creation system (MText) into the existing system landscape. For this, I independently develop several Spring Boot microservices that, among other things, 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 groups multiple calls and acts as a facade for communication with various services
• Developed a conversion service to transform unstructured XML files into structured JSON files for different business domains
• Extensive unit and integration tests for file conversions; mocking interfaces with WireMock, Aspects, etc.
• Unified exception handling with @ControllerAdvice and Aspects
• Professional design of OAS definitions (design-first approach)
• Generated client and server implementations based on OAS definitions (OpenAPI Specification) using code generators and managed them in Nexus
• Logging in conjunction with the ELK stack
• Connected 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
• Deployed 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

Certifying large solar plants in Germany poses a challenge for many companies. Authorities require a lot of information that companies must gather through tedious processes. CarbonFreed offers an AI-supported platform where all involved parties can enter, review, and evaluate the information together.

• Extensive automated Cypress tests
• Integrated tests into GitHub Actions
• Fixed minor frontend issues
• Master data management 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: AspNet 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 of these components is managed with SAP. This system tracks which parts belong to which machine, when they are delivered, and if they are still in stock. Unfortunately, the current SAP version does not offer extensive features to quickly and efficiently find 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 using a CSV file exported from SAP.

• Made technology and architecture decisions
• AspNet Core: parsed the CSV file and saved data to PostgreSQL
• Spring Boot: parts management using 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: AspNet 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 digitalization, parts of Euroglas GmbH's in-house IT infrastructure were adapted to modern technologies. Based on this, various modules were developed in the next step. One of these modules is a maintenance planner. It serves as an assistance system for maintenance to efficiently manage the servicing of hundreds of machines.

• Writing technical user stories
• Technology decisions and their implementation
• 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 orders to different employees
• Different views (maintenance planner and employee)
• Frameworks: NgRx, RxJS, Angular Material
• Setting up ASP.NET Core Identity for user management
• Integrating users from the internal Azure 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 (employee interviews, software to be replaced)

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 was developed for the Unity Asset Store that lets customers without programming knowledge create autonomously moving AI agents. The focus during development was on well-thought-out software design, professional API documentation with Doxygen, and application performance.

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