Microservices 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

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

• In this role, I was responsible as Lead Software Engineer for automating various meat production lines.
• My focus was on developing highly available (High Availability) systems using C/C++.
• I also implemented and supported container orchestration with Kubernetes to ensure smooth and scalable production operations.

• Project manager for banking projects

• 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

• 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

• Independent management consultant for the energy and real estate industry
• Interim manager at a municipal energy provider for sub-metering
• Strategic corporate development for an Austrian energy service provider

• Supporting the DevOps team in Terraform-managed, multi-region AWS infrastructure to achieve environment parity.
• Developed end-to-end CI/CD pipelines using AWS CodePipeline, CodeBuild, and CodeDeploy, automating the build and deployment.
• Maintained pre- and post-deployment scripts to automate critical tasks such as database schema migrations and environment sanity checks.
• Implemented CI/CD flow specifically for hotfixes via separate Git branches, managing back-merge activities from feature branches to release branches to ensure code integrity through automated conflict resolution.
• Deployed a dedicated, lightweight sanity check application hosted cost-effectively on Azure Container Apps to run automated health and basic functional checks as a post-deployment activity triggered via pipeline.
• Investigated production incidents through code changes and AWS CloudWatch logs.
• Coordinated integration of Dynatrace APM and its APIs for monitoring purposes.
• Full stack QA strategist for a high-traffic e-commerce platform built on a layered architecture for the back-end testing of core platform services, especially the order management system in Zed and Glue layers.
• Managed automation activities, testing process, and refactoring practices.
• Responsible for framework migrations, setup, and training for new automation frameworks.
• Promoted a shift-left approach within the QA team and created the test concept.
• Participated in meetings with IT managers, business owners, product owners, and team members.

• Migrated backups and full workloads to AWS and Azure, including setup and management of AKS & EKS clusters.
• Automated infrastructure with Terraform & ArgoCD and implemented CI/CD pipelines with GitLab.
• Monitored systems on OpenShift 4 (on-premise) with Grafana & Prometheus, using CloudWatch and X-Ray for analysis and logging.
• Built and maintained secure network infrastructures (VPCs, SGs, WAFs, ACLs), integrated Azure Log Analytics.
• Collaborated closely with infrastructure and development teams, maintained technical documentation with Confluence, handled tickets via Jira, and promoted cloud knowledge within the company.

• Mobile: Kotlin Multiplatform (KMP), Kotlin, Swift, SwiftUI, Jetpack Compose, Ktor, Room, Koin
• Backend: Spring Boot, GCP Cloud Run, GCP Load Balancer, GCP Eventarc
• Planned and developed a cloud backend architecture with Google Cloud Platform
• Developed a cross-platform architecture with Kotlin Multiplatform (KMP)
• Tech lead for comprehensive large project including webshop, two apps and omnichannel backend

• 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

• Solution architecture & development for a global commerce platform.
• Technologies: Spryker, PHP, AWS, SAP, VueJS

• Visualization, search, and maintenance of various types of master data, providing them via a REST API, and implementing a variety of import and export formats.

• Implementation, architecture, project management.

• Technologies and tools: Angular (Signals, Signal Store, swagger-codegen, standalone components), Java, PostgreSQL, ActiveMQ, JavaScript, Spring Boot (Spring Core, Spring MVC, Spring Data/JPA via Hibernate, Spring Security, Spring Modulith), JUnit, Flyway, QueryDSL, GraphQL, REST API, Node, npm, Maven, SonarQube, GitLab CI/CD pipelines, Docker, Nexus, OpenAPI + Swagger UI, Keycloak, OAuth2, OpenID Connect, IntelliJ IDEA, Jira, Confluence.

• Migration of a .NET Core loyalty program for Snipes, used by mobile cash registers in Snipes stores
• Part of the customer’s digitalization strategy in an agile, cross-functional team with a high level of ownership
• Connecting interfaces to third-party systems (e.g. Brandung, CDS)
• Quality assurance through automated tests
• Carrying out developer, unit, and integration tests
• Patterns & methods used: Clean Code, microservice architecture, agile development with SCRUM
• Technologies & tools used: Spring Boot, Java 23, Java Persistence API (JPA), Azure DevOps, Azure Key Vault, Azure PostgreSQL, Docker & Kubernetes, Git, Graylog, Grafana, JUnit, SonarQube, Jira, Confluence, Prometheus, GitLab, GitLab CI/CD, Visual Studio Code