Svelte Experts in Germany

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

• New development and further development of frontend interfaces for investors, using HTML5, JavaScript, CSS, React, Material UI, and JSTL

• Drive migration of enterprise authorization platform from Styra DAS to open-source OPA via Skipper (Zalando's Golang-based ingress proxy) integration
• Optimise k8s resources and integrate native Prometheus metrics with OPA
• Migrate from internal monitoring solution to Prometheus CRs + Dash0

Tech Stack: Java/Kotlin, Golang, Python, Spring Boot, AWS, Kubernetes, Docker, OpenTofu, Prometheus, Grafana

struppilog.com – Digital health record for pets / MVP → Full Product

Design, development, and full further development of a digital health platform for pets – from my own MVP development to a fully built and production-ready platform.

Independent concept and development of the MVP Development of the full application with Flutter/Dart and Firebase Expansion of the MVP into a full digital health record with health data, findings, allergies, medications, documents, and emergency data Development of user registration, authentication, roles, data models, and secure user interactions Implementation of QR-code-based data exchange and digital interaction features Development of a multilingual, responsive web application Integration of AI-supported features and AI/agentic workflows Development and continuous improvement of product logic, UX/UI, and technical architecture Building and expanding a scalable cloud-based solution with Firebase Integration and further development of APIs and external services Use of AI-native / agentic engineering to speed up development, testing, debugging, and product iteration Independent implementation of all other features and technical extensions Continuous further development of the MVP into a full digital product

Impact: The MVP I built myself was continuously developed technically and functionally into a broad, production-ready platform – including frontend, backend, data model, authentication, UX/UI, APIs, cloud infrastructure, and ongoing product development.

• Built a complete real-time multiplayer platform with game engine, lobby system, game tables, spectator mode, and persistent game history.
• Implemented product-relevant multiplayer workflows with WebSocket communication, live synchronization, voice chat, mobile app features, and push notifications.
• Developed a scalable full-stack architecture with authentication, PostgreSQL persistence, premium/billing integration, and extensive test coverage.

• Designed and implemented a hybrid recommendation system (content-based + collaborative filtering)
• Built end-to-end ML pipelines including data processing, feature engineering, model training, and evaluation
• Developed RAG-based LLM systems using LangChain and vector databases for semantic search and knowledge retrieval
• Established MLOps workflows with MLflow for experiment tracking, versioning, and deployment readiness
• Implemented deep learning models (computer vision & classification) using PyTorch and TensorFlow

• Taught German language and mathematics to children aged 4-16, providing homework assistance and tutoring
• Supported startups in UX, MVP development, and Lean Startup methodology
• Assisted with branding, communication, and design to strengthen market presence
• Maintained website and Venture Lab app; coordinated and ran events
• Developed presentations to support internal and external communications

• Design and development of an application for optimized material usage (cutting-stock problem)
• Visualization of cutting plans and integration into existing systems
• Architecture, frontend and backend development

Python, SQL, PySpark, Databricks, Databricks SQL, Delta Lake, dbt, Azure Data Lake Storage, Azure Machine Learning, Azure DevOps, Power BI, Git, MLflow

• Developed, validated, and optimized predictive analytics and classification models using Python (pandas), SQL, and modern ML frameworks.
• Performed data analysis, feature engineering, model validation, cross-validation, and stability analysis to ensure robust model quality and performance.
• Communicated model assumptions, results, uncertainties, and limitations to business units, management, and technical stakeholders.
• Built scalable data and machine learning workflows in cloud-based analytics environments using Databricks and Microsoft Azure.

• Built a fully responsive business dashboard with dynamic job analytics visualisation and CMS-integrated content hub (articles, audio, images) with on-demand media loading. Achieved Lighthouse scores of 100 (Accessibility, SEO) and 88 (Performance) on mobile.
• Implemented pixel-perfect UI from Figma designs across 6 pages, adding scroll-triggered animations and unit tests for critical user-input components.
• Reduced code duplication by ~20% by refactoring AI-generated frontend codebase into modular, reusable components, improving long-term maintainability.
• Accelerated development by integrating AI-assisted coding workflows and Model Context Protocol (MCP) tooling, as well as independently resolved backend issues without dedicated support.
• Technologies used: Svelte (SvelteKit), Tailwind CSS, Supabase, Sanity, GSAP, Chart.js, Vitest.

• Frontend development and implementation of various designs (landing pages, overview pages)
• Responsible for the content and updates of the Datalyze Solutions company website
• Joint planning and development of an admin application for listing and locating real estate projects (CBRE)
• Joint planning and development of extensive solutions for automatic staff allocation in plants (Bosch)
• Backend development of various small projects with different stacks
• Tech stack: GitLab CI/CD, Elixir, Phoenix Framework, Ecto, PostgreSQL, Docker, Hetzner, Traefik, NGINX, Python, Flask, Next.js/React, Leaflet, GeoServer, TypeScript, MongoDB

• Designed and developed the "Credit Risk Engine" using Camunda, Node.js and Typescript
• Greenfield project for credit card credit assessment for existing and new customers, including EBA KPIs, SCHUFA and CRIF scorings
• Built and modeled workflows (BPMN) and decision logic (DMN) with Camunda Modeler in close collaboration with stakeholders
• Implemented service tasks, user tasks and jobs with Nest.js, Node.js and Typescript, including exception handling
• Backend-for-Frontend (BFF), frontend with React, Tailwind and Ant Design UI library
• CI/CD with GitLab, Kubernetes/Rancher