Grails Experts in Germany

• Overall technical responsibility for innovative SAP Customer Checkout solutions for leading customers such as Aramark, Consortium Gastronomie, Feinkost Käfer, TSG Hoffenheim, and VfB Stuttgart. End-to-end support from requirements analysis through implementation and support.

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

• Development of the software architecture and implementation according to Modern Android Development principles.

• Management of a small development team (1 Android expert, 1 working student) with a 50 % share of my own development work.

• Integration of various payment SDKs (S-Payment S-POS, VR Payment, CCV), enabling customers to achieve significant cost savings by continuing to use existing contracts.

• Successful rollout at several major customers, with demonstrably increased efficiency of sales staff.

• Independent development and successful implementation of critical infrastructure components:

• Reporting server (SQL, JasperReports): Demonstrable reduction in accounting workload by eliminating the need for daily manual data transfer to the ERP system.

• ZVT plugin: Sole responsibility for implementing the serial protocol with Java/Netty over TCP/IP, saving several thousand euros per site and successfully used in production at several Bundesliga stadiums.

• Complete independent development of specialized plugins and server applications for customized extensions of SAP Customer Checkout:

• Waiter Teams Plugin: Enables waiters to work and settle accounts as a team.

• SQL Reporting: Independently delivered from concept through complete documentation.

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

• Integration with reservation services: Designed seamless integration with Luca and other services and implemented it together with a colleague.

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

• Development of a test system
• Establishment of the architecture using Scala/Java for the backend and Swing for the frontend
• Setup of CI/CD pipelines with Jenkins for continuous integration, including automated builds
• Participation in the Scrum team, including daily stand-ups, sprint planning, and retrospectives
• Technology environment: Scala, Swing, EJB, JPA, Scrum, PostgreSQL, Mercurial

• Designed and developed scalable backend systems using Java, Spring Boot, and AWS services.
• Contributed to HWP (Human Work Planning), a modern, cloud-based planning and optimization system for assembly and manufacturing processes across the Volkswagen Group. The platform provides a standardized digital solution for planning, optimizing, and supporting the simulation of human work and production process flows.
• Helped modernize legacy applications by migrating them to modular, distributed architectures, improving scalability and maintainability.
• Collaborated with cross-functional teams across Germany, the Czech Republic, and Tunisia in a SAFe Agile environment.
• Utilized Bitbucket for version control, Bamboo for CI/CD pipelines, and JIRA for project and issue tracking.
• Integrated AWS services including EKS for container orchestration, Batch for job scheduling, and CloudWatch for monitoring.

Tech Stack: Java, Spring Boot, AWS (EKS, Batch, CloudWatch), React, SQL, Bitbucket, Bamboo, JIRA

• Extended the document management system with a standard CMIS (Content Management Interoperability Services) interface
• Implemented CMIS core services like navigation, access rights, search, CRUD operations, and versioning in Java
• Implemented based on RESTful / OpenAPI services
• Delivered as a fat-jar and native container image
• Deployed on-premises and serverlessly as an Azure Container Application using Terraform
• Improved team autonomy through infrastructure engineering and short feedback loops
• Established observability with OpenTelemetry, Azure Monitor, and Azure Logic Apps
• Introduced Terraform and trunk-based development processes
• Ensured quality with BDD tests in C# using SpecFlow and Testcontainers
• Created Azure DevOps pipeline integration tests
• Introduced cloud deployment processes
• Trained staff in cloud and Terraform

• Development of a future 3D configurator for creating Jungheinrich pallet racks in all variations as part of Jungheinrich AG's digitization campaign
• Development and extension of the UI with Configura Magic
• Implementation of 3D rendering and interactions
• Preparation of data for structural calculations
• Parts list management and dynamic price calculation
• Database maintenance for individual parts and assemblies
• Support in integrating with SAP
• Languages used: C# and Configura Magic

• Web developer for digitizing business processes, specializing in the AI software Parashift and development using JobRouter