REST API Experts in Dusseldorf

• Training the AI models, evaluating images and texts for UI/UX, turning the provided data into insights via OpenAI Feather as part of the machine learning workflow

Technologies: OpenAI Feather

• Acquires new B2B customers for an AI SaaS startup in the public tendering space and books product demos with IT decision-makers.
• Qualifies target customers based on a defined ideal customer profile, including discovery, needs analysis, and objection handling.
• Builds domain knowledge in public procurement (EVB-IT, German and EU tender portals) for technical discussions at eye level.

PLANT-MY-TREE®-per-order

The application enables Shopify merchants to automatically place tree-planting orders for every incoming order. By integrating ecological contributions directly into the purchase process, the manual effort for tracking and billing reforestation initiatives is eliminated. The system increases transparency for end customers through real-time visualizations of the ecological impact directly in the storefront. The architecture is based on a modular monolith with Spring Boot in the backend and an integrated React app inside the Shopify admin area. The solution uses webhooks to capture order data in an event-driven way and integrates the weclapp ERP system for automated monthly invoicing. An app proxy mechanism provides dynamic statistics such as CO2 compensation and planted trees without any performance loss for the merchant shop.

Tasks:

• Design of the modular software architecture based on Spring Modulith to ensure high maintainability
• Development of the event-driven business logic for evaluating Shopify orders via webhooks
• Implementation of automated invoicing by connecting the weclapp REST API
• Building the frontend using React Router and Shopify App Bridge for native integration
• Design of the database model and implementation of the persistence layer with JPA/Hibernate and Prisma
• Integration of internationalization processes for global use in the frontend and email communication
• Automation of deployment processes using Docker and GitLab CI/CD

Project skills: Java 25, Spring Boot, Spring Security, Spring Modulith, Hibernate, JPA, REST API, PostgreSQL, Maven, Liquibase, React, TypeScript, React Router, Vite, Node.js, Prisma, Zod, Docker, Docker Compose, GitLab CI/CD, Shopify CLI, Shopify App Bridge, Polaris, weclapp, i18next, Lombok, Vitest

• Identification of requirements (legal, organizational, and technical)
• Design of solution architectures
• Evaluation of concepts and technologies
• Preparation of decision templates
• Architectural Decision Records (ADR)
• Coordination of implementation
• Review of implementations
• Documentation

• Architected and deployed a live B2B geocoding and demographic-data platform for Germany, combining address lookup with census-based population statistics through a web application and REST API.

• Analysis and remediation of security vulnerabilities in a risk assessment system for energy trading
• System analysis
• Threat modeling
• Decision-making on vulnerability mitigation strategies
• Implementation of vulnerability detection mechanisms
• Security scans
• DevSecOps practices
• Technical environment: Visual Studio Code, JetBrains Suite, MS Threat Modeling Tool, DevSecOps, Git, AWS, DynamoDB, SQL Server, Endur, Snowflake, Orca
• Languages: C#, JavaScript, TypeScript, Python, PowerShell, Bash, Terraform, SQL

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

• Deriving test cases in IBM DOORS for various devices according to ISTQB
• Automating and running test cases in Python under Linux
• MobaXtrem, Windchill are in use

• Architecting and developing SaaS platform for graphical definition and execution of pandas data processing pipelines
• Developed POlyglott, an open-source Python CLI tool for translation workflow management featuring PO file parsing, quality linting with glossary enforcement, and DeepL API integration for machine translation
• Developed web application for material compliance management (EU REACH) using Django and modern web technologies
• Built automated infrastructure platform using Proxmox, Terraform, and Ansible — VM provisioning, configuration management, internal DNS, and fleet-wide security hardening across multiple subnets

• Development of the SmartHub platform for RepairX.io (iOS app & web)
• Development of an AI-powered (clinical decision support) patient management platform for the Malteser Hospital to provide care for uninsured patients
• Development of a retrieval-augmented generation (RAG) system for the intelligent processing of medical data for ASCEND gGmbH
• Design of an AI-powered system for emotion analysis of guests and development of AI agents for automated accounting and compliance checks
• Planning of the RepairX.io platform (circular economy) and management of a DAO Hyperledger blockchain system for NGOs
• Development of internal audit systems for AI ethics violations in healthcare (according to the EU AI Act)

• Full focus on AI-augmented web development
• Building and running three proprietary AI-native SaaS products (BrainButler, PageUpgrade, termin365)
• Developing a self-hosted business stack for digital sovereignty
• Daily workflow with Claude as engineering partner and Anthropic/OpenAI APIs for product features
• Using RAG systems with custom vector databases and prompt engineering for complex multi-step pipelines
• Tech stack: Python/FastAPI (backend), React/TypeScript (frontend), WordPress plugin architectures (PHP), multi-tenant systems with per-user encryption

• Led SampleManager LIMS 21.x & LabWare LIMS v8 implementation, reducing manual lab errors by 40% and improving data traceability.
• Configured LW LIMS & SM LIMS 21.2: workflow design, role-based access control (RBAC), and master data management.
• Designed and configured LES workflows: sample lifecycle management, test assignments, approvals, and result review processes.
• Managed Master Menu and CI configuration, ensuring consistency, data integrity, and regulatory compliance.
• Integrated LIMS 21.2 with MES, ERP, EM, WinKQCL (Lonza MODA), SoftMax Pro, Empower, and Chromeleon CDS via REST APIs and web services.
• Implemented PAS-X MES: architecture design, multi-platform implementation (PAS-X, Siemens Opcenter), and integration with PLC, SCADA, and DCS systems.
• Executed IQ/OQ/PQ qualification protocols and Validation Summary Reports (VSR) for QC analytical and utility systems in aseptic and sterile production environments.
• Developed and reviewed Risk Assessments, Traceability Matrices, and Data Integrity evaluations in accordance with ALCOA+, 21 CFR Part 11, and EU Annex 11.
• Led EMA/FDA/WHO inspection readiness, standardized CQV SOPs, enabled digital CQV integration (LIMS/CDS/MES/SCADA/ERP/SDMS), and ensured 21 CFR Part 11 & Annex 11 compliance.
• Managed secure OT cybersecurity: network configuration and access control.
• Configured NuGenesis SDMS for document/data management, CDS/LIMS integration, workflow automation, and reporting.

• Design, development, and execution of load and performance tests for the PRISMA project
• Use of Apache Jmeter, Gatling, Apache ActiveMQ, Jms/Tibco Ems, SikuliX, Jython, Amazon AWS, PAN-Client
• Methods: load tests, test automation

• Built and launched the AI-powered “E-Invoice Corrector,” an intelligent system for validating and correcting invoices, using Python, FastAPI, and machine learning. The system is now live at Fintom8.
• Converted the Corrector into a fully functional API, published with Swagger documentation for easy access and integration by internal and external consumers.
• Designed, experimented with, and optimized advanced LLM prompts and meta-prompting strategies to improve automated reasoning, error correction, and decision-making in agent workflows.
• Wrapped and integrated existing APIs within the Google Agent Development Kit (ADK) framework to enhance automation capabilities and conversational AI workflows.
• Implemented comprehensive unit testing using pytest and unittest, and employed breakpoint debugging (VS Code, pdb) to ensure code reliability, maintainability, and smooth runtime execution.
• Utilized Pydantic and Tabulate for structured data validation, API schema management, and clear tabular data representation in testing and debugging workflows.
• Pursuing the Google Cloud Professional Certificate.