React Experts in Cologne

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

• Building an AI-native coaching platform for cyclists: a conversational Dynamic Coach that turns training and recovery data into the next session decision, available daily instead of a static calendar.

• Designed and shipped a full-stack, chat-first coaching experience on Next.js and the Vercel Edge Network, with agentic workflows that adapt plans in real time to readiness, load, and life constraints.

• Built integrations with Garmin, Strava, Whoop, and intervals.icu so sleep, HRV, and ride data feed coaching recommendations without manual data entry.

• Product thesis: make high-quality coaching principles accessible at scale by combining adaptive training logic with plain-language conversation, not another metrics dashboard.

• Built more than 15 frontend applications and more than 10 backend services across internal tools, back-office workflows, and external portals for installers and end customers
• Automate build and release workflows with TypeScript and Azure DevOps
• Mentor junior engineers through code reviews and technical guidance
• Integrate AI-assisted and agentic development practices into engineering workflows
• Coordinate user experience decisions with UX designers

Tech Stack: Claude Code, Codex, AWS (S3, Lambda, AppSync, Resolver), Next.js App Router, ReactJS, NuxtJS, Vue.js, Storybook, JavaScript, TypeScript, GraphQL, Azure DevOps

• Backend WordPress web development.

• Regulated environment within a German banking group (approx. 8,500 employees, hybrid cloud strategy).

• Responsible for operating, provisioning, and continuously securing business-critical platforms – including a GenAI chat application, a big data/AI platform, and data science workspaces based on Azure Virtual Desktops and VMs. Ownership of Azure DevOps projects for ShaiHulud and React2Shell, as well as BSI alerts – Security Operations improvements across the SDLC.

• Deployment responsibility for the GenAI chat application, big data/AI platform (BDAI), and data science workspaces (AVD/VM-based) in the respective landing zones.

• Deployment & release management: end-to-end responsibility for deploying portal and service applications across multiple Azure landing zones, including technical approvals, compliance with development team deployment guidelines, and ensuring ITIL-based change and release processes via ServiceNow.

• Azure landing zones & network architecture: design, provisioning, and operation of Azure landing zones for 3-tier web applications with enhanced network segmentation, VNet peering, hub-and-spoke architectures, private endpoints, and firewall integration across separate subscriptions and tenants.

• Azure DevOps governance & operations: ownership of the Azure DevOps organization, including projects, repositories, and CI/CD pipelines; implementation of governance requirements such as branch policies, approval gates, permission models, and audit-ready operating structures.

• Infrastructure as Code (Terraform): design, implementation, and operation of a modular Terraform architecture for standardized cloud infrastructure deployment, including state management, provider versioning, reusability, and policy-as-code approaches.

• CI/CD pipeline engineering: design, operation, and optimization of complex YAML-based CI/CD pipelines with multi-stage deployments, template standardization, self-hosted agents, integrated secret management, and automated quality and security checks.

• Git migration & platform consolidation: planning and execution of repository and pipeline migration from Azure DevOps to GitLab CI/CD, including automated scripts, full Git history transfer, pipeline porting, and platform consolidation.

• Container & platform operations (AKS): operation and security assessment of containerized workloads on Azure Kubernetes Service, centralization of on-premises container registries for ACR.

• OpenShift (OCP) security reviews: security assessment of code baselines, build pipelines, and deployment processes for on-premises OpenShift clusters with critical applications, and derivation of specific hardening recommendations.

• Shift-left security & DevSecOps transformation: introduction of a company-wide shift-left approach for early security integration in development and deployment processes, enabling developers to perform self-led security checks and sustainably reduce vulnerabilities before production (IDE integrations, pre-commit hooks, local scanners).

• Software supply chain security: analysis and mitigation of supply chain risks in NPM- and Yarn-based applications through dependency audits, CI/CD pipeline hardening, token rotation, and restriction of risky build and lifecycle mechanisms.

• Frontend & framework security (React / Next.js): security assessment and coordination of critical vulnerability remediation across platform applications and web frameworks, including coordination and complementary technical mitigations with all teams following BSI alerts.

• Software composition analysis (SCA): introduction and operation of automated vulnerability scans for container images, pipelines/artifacts, and third-party dependencies, including SBOM exports within CI/CD pipelines.

• SAST/DAST integration: design and piloting of static and dynamic application security tests in close collaboration with security architecture and development teams, for continuous improvement of code and runtime security, and establishing operational acceptance tests.

• Artifact & registry consolidation: analysis and consolidation of all package and container repositories for service applications and AKS workloads, aiming for a centralized, secured registry strategy with centralized vulnerability scanning and governance.

• Dependency-Track & SBOM strategy: advising the compliance board on introducing a central SBOM and vulnerability management platform to increase enterprise-wide dependency transparency and accelerate CVE response capability.

• CI/CD pipeline hardening: security analysis and cleanup of the existing pipeline landscape by removing unused pipelines, improving secrets hygiene, implementing least-privilege principles, and isolating build agent environments.

• Azure Web Application Firewall (WAF) optimization: analysis and tuning of existing Azure WAF rules (OWASP Top 10 Core Rule Set, DSR/SDC, custom rules) to defend against known vulnerabilities and exploit patterns, including reducing false positives and improving threat detection.

• Documentation & stakeholder communication: creating and maintaining technical documentation, runbooks, and architecture overviews in Jira and Confluence, as well as active knowledge transfer between operations, development, security, and compliance stakeholders.

• 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

• Full product responsibility from a business perspective: requirement analysis, UX design, product strategy, and go-to-market implemented without an internal dev team using fully AI-supported development (Claude Code / Anthropic)
• Technical differentiation: KRITIS-compliant air-gapped deployment (Windows/NSIS), GDT interface for PVS integration, DATEV-LODAS export for payroll
• Managed pilot operation with initial external client (Dormagen medical practice): structured requirement gathering, test support, error analysis, and release management
• Developed rollout and sales strategy for market entry in the segment of private practices and small medical centers
• Human-in-the-Loop development principle: business decision → AI implementation → manual review → approval → release – each sprint documented in Jira (TIME project), every change traceable via co-authored commits
• Product outcome: Tauri/Rust desktop app with GDT watcher, multi-tier model (Starter/Professional/Enterprise), cloud mirror on Hetzner/Traefik, complete ISMS framework based on ISO 27001 and BSI basic protection as product foundation
• Direct method validation for the test manager role: hands-on experience with quality assurance of AI-generated products from a user perspective, review gate discipline, release approval under GDPR and the EU AI Act

• Responsible for the architecture and development of an AI-native SaaS platform for industrial product portfolio management.
• Designed the modern data platform architecture on Azure for scalable analytics and enterprise data integration.
• Built enterprise data ingestion and transformation pipelines across complex industrial system landscapes.
• Developed graph-based representations of product structures and dependencies for analytical reasoning.
• Designed and implemented an agentic AI framework for AI-supported decision workflows.
• Built scalable analytical microservices and integrated reporting through modern BI technologies.
• Coordinated backend, AI, and frontend development across the MYNR platform stack.

• Developed a shop website
• Integrated an AI language model
• Developed tools for AI-powered webhooks
• Technical tools: REACT.js; Elevenlabs; MCP; n8n; HTTP

• Two-month modernization of the management UI for AI-powered cameras
• Rewrote a complex React application to Vue 3 with single file components
• Set up the core architecture of the Vue application and configured Vite, Pinia, Router, I18n, ESLint, and Prettier
• Custom integration of Leaflet to display detection zones on images
• Assisted with backend extension and authentication adjustments

• Java 11/21

• Springboot

• Swagger/OpenApi

• Azure Pipelines

• Trivy Integration

• Apache Sling

• OSGI

• Java Content Repository (JCR)

• Apache Jackrabbit Oak

• Adobe HTL

• GraphQL

• Maven

• GitLab

• IntelliJ

• Azure Cloud

• Azure DevOps

• Terraform

• AEM specialist in the Scrum team

• Development and deployment of microservices via Open API interfaces

• Operation of microservices in the Azure Cloud

• Implementation of AEM modules and integration with microservices

• Member of the knowledge transfer team and a backend coordination team

• Designed and deployed a cloud-based grocery list app using AWS EC2 for hosting and RDS for persistent data storage, achieving 99.9% uptime across all test environments
• Reduced average response time by 2× through efficient deployment logic and optimized database queries, resulting in a smoother user experience across devices
• Utilized AWS (EC2, S3, RDS, IAM), Azure basics, Terraform, CloudFormation, Docker, Kubernetes basics, Jenkins, GitHub Actions, TCP/IP, DNS, Python, Bash scripting

• Build a sophisticated AI copilot to augment the students’ learning experience and provide AI-derived insights to professors.
• Build a multi-chain LLM system adapting to user needs at its own accord with a Weaviate vector DB based RAG system and evaluated it with Ragas.
• Build responsive react frontend, and backend systems handling auth, data management and auxiliary services as a RESTful API.
• Deployed and managed the app to the cloud in a production environment including the CICD via multi-stage deployment.