MySQL Experts in Cologne

Project: Introduction of statutory-compliant electronic invoicing (outbound, Germany) in SAP for an international technology group.

• Project management: Planning, steering and reporting of the E-Invoicing outbound rollout across all affected business areas, including budget and resource coordination.
• UAT: Structured user acceptance test with key users per business area, test cases per invoice scenario, and consolidated test results for decision making.
• Defect management: Handover and tracking of defects in Jira, including validation of the generated invoices against the statutory schemas.
• Cutover, go-live and hypercare: Readiness checks and cutover planning aligned with the statutory deadlines, coordination of go-live and stabilization during hypercare.
• Stakeholder management and reporting: Alignment with Finance, Tax, business departments and IT, preparation of status reports and decision papers, and consistent follow-up of open items.
• Change management and documentation: Communicated process changes to the business departments, enabled key users, and created process and compliance documentation to ensure traceability and audit readiness.

Successful delivery of projects on behalf of customers:

• -> 2023 – present: Project management for the consolidation of sites/data centers for a large telecommunications provider (infrastructure project, customer: Telefonica)

• Opening and preparing new sites

• Application migrations

• Decommissioning and handover of old sites

• -> 2021 – 2022: IT multi-project management for a large car leasing company (customer: Athlon)

• Migration of applications to the cloud and to another data center

• Additional projects to expand and optimize the application landscape

• -> 2021: Project management for the development of a platform providing internet access on aircraft operated by various airlines (customer: m3Connect/German Telekom)

• -> 2017-2020: Responsible management of an IP network consolidation (infrastructure project, customer: Cisco/Vodafone) at a large telecommunications provider

• Planning and coordination of migrations and their rollout

• Team leadership and integration of different teams (network operators, hardware and service providers)

Software engineering and integration consulting for enterprise clients, with a focus on backend development, APIs, system integration, and event-driven architectures. Currently developing and evolving a recruitment and staffing platform using Elixir and RabbitMQ, including asynchronous, event-driven communication and integrations with external recruitment and staffing platforms.

• SPA for automated communication of medical findings with role-based access (Sanctum)
• Server-side LLM integration (OpenRouter) with structured processing
• Automated sending via SMS/voice call (Twilio, ElevenLabs) with queue + status retry
• Full test coverage with 80+ documented test cases

Technologies: PHP, Laravel, LLM API (OpenRouter), Twilio, ElevenLabs, Laravel Sanctum, PHPUnit, Playwright, Docker, REST

• Determining the current status (planning status / expansion status) of the so-called interpolygon routes
• Preparing an end-to-end project plan for the individual routes, taking active and passive components and activities into account
• Monitoring and controlling plan implementation
• Optimizing the selected network architecture
• Creating network and splice plans

• PRISMA project
• Ansible automation
• Windows third-level support for Windows NT, Windows 2000, Windows 2013, Windows 2016, Windows 2019

• Automation of the database major / minor releases for the TKeasy project

• Concept for database major / minor release automation

• Assessment of the current state

• Evaluation of Redgate Flyway functionalities

• Concept development

• Products: Redgate Flyway, GitHub, Quest, Erwin Data Modeller, Oracle, Atlassian Jira, Atlassian Confluence

• Knowledge: Docker, Continuous Delivery, Continuous Integration, Redgate Flyway, Major Releases, Minor Releases

• Further development of the existing e-commerce platform based on SAP Commerce (Hybris) to meet the growing demands of digital commerce.
• Ensuring the scalability and performance of the backend, so the platform remained stable and efficient even under heavy user load.
• Development and integration of new OCC REST APIs and services for modular extensions and flexible adjustments, to implement new features quickly.
• Optimization of data flows and interfaces, which significantly improved platform efficiency and system performance.
• Ensuring a maintainable and scalable code base by using Clean Code principles, proven design patterns, and a future-proof architecture.
• Reduction of errors through extensive testing with JUnit, Mockito, and load tests with Gatling, supported by the introduction of automated test processes.
• Improved system performance through targeted refactoring measures and efficient database queries, especially to handle peak loads.
• Use of modern cloud and monitoring tools such as Kubernetes, Google Cloud Platform (GCP), and Grafana to ensure a stable and monitored infrastructure.
• Clear improvement in efficiency, scalability, and reliability of the platform, which now meets the demands of a dynamic and growing e-commerce market.

• Independently initiated and deployed automated validation workflows using Python, cutting manual processing by 58% and improving efficiency
• Developed a machine learning model for synthetic defect generation, reducing downtime and production costs; deployed locally and via Databricks and Azure AI Factory
• Utilized a small dataset of image data from the production lines and extended this dataset with training on models like cycleGAN and pix2pix
• Built and optimized the Linux-based development environment for training 3D models; maintained reproducibility via GitHub
• Presented technical insights to cross-functional teams (engineers, QA, project managers), ensuring alignment of ML solutions with operational needs

• Design, planning and execution of complex acceptance tests for a document exchange platform for the German justice authorities.
• Validation of decrypted and certificate-based message exchange via web platform, mobile app, and Java API.
• Documentation of test cases, execution steps, and test results.
• Technologies: Windows 11/10, Ubuntu, iOS, Android, Bash for Windows, Java 17, IntelliJ, Git, Jira, Confluence, Citrix Server, xJustiz standard implementation, specific justice software.

• Coordination and planning, execution, documentation, and analysis of test cases
• Development of test concepts considering best practices (e.g., test pyramid) with a focus on reliable, automatable test runs
• Implementation and maintenance of test cases according to the test concepts
• Technologies: Citrix Workspace, Shopify, Jira, Xray, MS Teams, MS SharePoint, Confluence, MS Office 365

• Further development of a policy administration system (contract/claims) for the legal expenses insurer ÖRAG.
• My role: Senior Software Developer.
• The team consists of 12 developers.
• Technologies used: Java 8/21, Java EE, Quarkus, WebLogic, JPA, RabbitMQ, JTA, CI, CD, Jenkins, DB2, Maven, Jenkins, GIT (bitbucket) later GitLab, Junit, Elasticsearch, Mockito, Jira, SonarQube, Scrum, React, Workflow
• Migration and modernization of legacy systems: rewrote C and C++ code in Java to improve maintainability, scalability, and performance. Refactored Python into Java, including optimization and integration into modern architectures.
• Study on the use of AI (Codex) for implementing a Java feature. The goal is to compare the time spent and productivity of AI-supported development with a classic implementation by a developer. The results should show how strongly the use of AI affects development time and efficiency.
• Development of the following tariff calculators for the years 2024/2026: private, companies, doctors, farmers, owner-occupied G + H, landlords, traffic, club, top managers, sales representatives, special criminal law, savings bank, municipal, BayGT, doctors, Dehoga

• Worked on FPGA enhanced network encryption device with secure boot, TPM2.0 and smart card integration for BSI approved usage with Post Quantum Cryptography
• Developed and audited Linux drivers
• Collaborated using GitLab, Gerrit, Confluence and Jira
• Technologies: C, C++, Secure Boot

The Helaba ATLAS project aims to modernize core systems and make them future-proof. As part of the subproject, the existing legacy system for international payments is being replaced by a modern web-based application.

• Analysis of functional and technical requirements
• Analysis and optimization of business processes
• Process modeling
• Preparation and facilitation of workshops
• Defining project scope and prioritizing requirements
• Business process management (analysis, modeling, and optimization)
• Specification of user stories
• Designing business and authorization concepts
• Testing and acceptance
• Designing mockups in Figma
• Creating the UI/UX style guide for web applications Approach: Scrum (agile) Technologies: Jira, Confluence, MS Teams, Conceptboard, Java, Vaadin, Figma