PostgreSQL Experts in Düsseldorf

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

Technologies: OpenAI Feather

• Created data pipelines and visualization tools to support sustainable energy decision-making
• Developed insights that could optimize renewable energy deployment and grid integration strategies

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

• Title: Enhancing Syntactic Awareness in Transformer Language Models for Hindi Dependency Parsing
• Investigated syntactic knowledge captured by transformer language models (RoBERTa, XLM-RoBERTa) for Hindi dependency parsing, a morphologically rich and low-resource language.
• Developed structure-aware model variants (Struct_Roberta_hi, Struct_XLMR) by integrating a CNN-based parser network between transformer layers, inspired by the StructFormer architecture.
• Conducted extensive error analysis including label-wise, distance-based, direction-based, sentence length-based, and LVC/Non-LVC evaluations.
• Evaluated models on downstream NLP tasks (NER, POS tagging) using the IndicXTREME benchmark.

• Project Manager for banking projects
• Management and coordination of the projects 'XONTRO T7 Migration' and 'UNO – Unified for New Opportunities'. Management of international stakeholders, preparation and leadership of steering committees, and coordination between departments, exchanges, and external partners.
• Project management of the strategic projects 'XONTRO T7 Migration' and 'UNO – Unified for New Opportunities'
• Management of international stakeholders including exchanges, custodians, and external project partners
• Coordination of functional and technical test activities at the exchanges between trading, IT, accounting, and mid-/back office
• Facilitation of steering committees at management level
• Preparation of decision papers, status reports, and risk analyses
• Conduct analyses in the areas of reporting (compliance, regulatory reporting, etc.), taxes on securities transactions & custody accounts, process analysis
• Enforcement of required requirements/specifications
• Coordination between business, IT, operations, and external market participants
• Coordination and alignment with external market participants, service providers, exchanges, and other project stakeholders

(Maternity/Parental Leave: July 2023 – Aug 2024)

• Domain: Payment Domain | Client: Telefonica Germany
• Project: General Payment Service

The General Payment Service is responsible for processing of online payments via external payment service provider like Safer pay and PayPal

• Developed Design of Use (DOU) and interface contract documentation, ensuring clarity and compliance across system integrations
• Designed and delivered REST/SOAP web services with Spring Boot and Spring Data JPA, publishing Swagger contracts through WSO2 API Gateway to improve accessibility and governance.
• Spearheaded the on-premises to AWS Cloud migration, re-platforming from Oracle to PostgreSQL on AWS RDS and deploying services on EC2, improving scalability and cost efficiency.
• Containerized microservices using Docker and orchestrated deployments with Kubernetes, streamlining deployment pipelines and improving system reliability.
• Implemented proactive monitoring and logging via AWS CloudWatch and Kibana, ensuring stability and performance during cutover.
• Enhanced collaboration through code reviews and peer reviews, promoting maintainability and clean coding standards.
• Strengthened quality by writing comprehensive JUnit tests and preparing detailed test cases enabling early defect detection
• Delivered automated API testing with Ready API, Postman, and SOAPUI, and conducted performance testing with JMeter, ensuring reliability in high-transaction environments.

• 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

• Contributed to the development of an advanced RAG AI Chat application that integrates multiple LLM models, enabling users to seamlessly switch between models based on specific tasks. This improved the user experience by providing tailored, efficient solutions for various use cases, such as event scheduling, booking systems, and complex task management.
• Participated in designing and implementing a robust backend architecture using Spring AI, enabling advanced AI-driven capabilities like intelligent task automation, language processing, and contextual recommendations. Leveraged Spring AI Tools and Advisors to enhance the performance and decision-making of the AI models.
• Collaborated on the integration of vector databases to support embeddings, enhancing the app's ability to understand user queries and perform actions based on complex, real-time data inputs.
• Contributed to the development of a seamless, user-friendly front-end interface using React with TypeScript support, ensuring a modern, responsive, and scalable user experience across platforms.
• Assisted in implementing state management with Redux RTK for efficient data flow and real-time updates, optimizing the overall user experience in dynamic scenarios such as scheduling and task management.
• Partnered with stakeholders to define feature requirements, helping ensure that the app could scale to meet evolving business needs and integrate with other systems like calendar and email services. Worked alongside cross-functional teams, including data scientists and UI/UX designers, to fine-tune AI models and ensure alignment with project goals.
• Contributed to ensuring end-to-end system performance, security, and compliance by helping integrate authentication mechanisms, role-based access control, and secure communication protocols in both backend and frontend layers.

Technology Stack and Key Contributions:

• Java / Spring Boot / Spring AI: Developed backend services leveraging Spring AI for intelligent responses, task automation, and complex workflows.
• React / TypeScript: Built intuitive user interfaces with React and TypeScript, ensuring a smooth and scalable frontend.
• Redux RTK: Managed application state with Redux RTK for optimized state management, enabling dynamic, real-time data updates.
• Vector Databases: Integrated vector databases (pgVector) for embedding support, improving AI model performance in handling complex queries.
• PostgreSQL / Redis: Managed persistent and temporary data with relational and in-memory data stores, ensuring data integrity and speed.
• Kafka: Utilized Apache Kafka for event-driven communication and seamless integration between microservices.
• Spring Security: Ensured the security of backend services with robust authentication and authorization mechanisms.
• CI/CD & DevOps: Integrated continuous integration and deployment pipelines to ensure rapid and secure deployment of features and updates.

• Responsible for the entire software architecture of the parental allowance portal
• iOS and Android app with React Native and Expo, incl. push and OTA updates
• Store releases via App Store Connect and Google Play Console
• TypeScript monorepo for app, website and backend, web with Next.js and Tailwind
• Own promo, voucher and discount engine with contact and segment logic
• Payments via RevenueCat and in-app purchases, authentication with BetterAuth
• REST APIs based on OpenAPI, PostgreSQL with Prisma and Drizzle
• Self-hosting on Hetzner with Docker, Coolify, Terraform and GitHub Actions
• Tests with Vitest, Playwright and visual regression via Chromatic
• Observability via Grafana Cloud and error tracking with Sentry
• Performance marketing via Meta Ads, measured with custom event tracking
• Grew the product to 20,000 app users with a purchase rate of almost 12 %
• Managing Director since 04.2025, responsible for product and technology

• Supporting several agile teams in the new product development of an enterprise CRM and ERP application
• Web frontend development with Angular 17–21 (microfrontends, Domain-Driven Design, MDB-Bootstrap)
• Backend development with C# and .NET 7–10, MongoDB, MassTransit, RabbitMQ, Entity Framework Core, ElasticSearch (microservices, DDD)
• Technical feature design for assigned tasks
• Technical architecture design including forward-looking planning of AI-supported extension options
• Proof-of-concept implementation of AI-supported workflows with n8n and a locally hosted LLM (Ollama)
• Coordination with stakeholders and Product Owners, support with sprint planning

Result: Delivery of production-ready microservices and frontend modules in agile sprint cycles.

Environment: .NET 7–10 · Angular 17–21 · C# · TypeScript · OpenAPI · Microfrontends · DDD · Kubernetes · Docker · Helm · MS SQL Server · PostgreSQL · MongoDB · MassTransit · RabbitMQ · EF Core · ElasticSearch · Kibana · Azure DevOps · KeyCloak · n8n · Ollama

• Development and maintenance of database-driven applications for managing supplier and food contracts, with extensive use of Oracle PL/SQL for complex business logic and data processing
• Optimization of PL/SQL procedures, functions, and triggers to ensure the performance and scalability of Oracle database solutions
• Ensuring compliance with best practices in PL/SQL development and implementing standards for code quality and data integrity
• Close collaboration with backend and frontend teams to ensure smooth integration between the Oracle database, C#-based APIs, and Azure cloud services

• 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

• 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

• 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