OAuth Experts in Hamburg

• Developing a professional scheduler for organizations with specific detailed requirements
• Evaluating different existing software solutions
• Creating a list of technical requirements
• Implementing these requirements
• Selected technologies: WebDAV, CalDAV, Rust, Baikal, OAuth, Keycloak

• Project lead ‘Cloud Migration’ for moving the on-premise production environment to Scaleway.
• Transformed a Docker-Swarm legacy setup to a modern Kubernetes-based cloud environment.
• Architected a GDPR-compliant cloud landscape and deployment setup – 100% European sovereign cloud.
• Hands-on bootstrapped the cloud environment with Terraform, ArgoCD, and GitLab Pipelines CI/CD.
• Replaced the legacy VPN with modern mTLS PKI and deep AD integration.
• Managed an 11-headed agile team using Kanban, moderating team meetings and plannings.
• Successfully finished the migration, moving infrastructure, services, and data, from planning to execution.

As a bridge between Legal, IT, and Marketing, my responsibilities include conducting technical due diligence, documentation, and designing privacy-compliant IT functions across multiple B2P Telefónica Germany brands as part of the RAITT digitalization program. Focused on aligning web and app services with GDPR, TDDDG, and Privacy by Design & Default principles.

Core responsibilities included analysing and visualising data flows across customer journeys, validating tracking and martech integrations, and supporting IT teams in designing privacy-compliant digital architectures. Delivered documentation for internal legal assessments and maintained OneTrust governance and cookie-banner accuracy.

Services and technologies involved:

• Identity & Authentication: CIAM (OAuth2, OIDC), login and session handling, customer account services
• Analytics & Measurement: Google Analytics (GA4), Google Tag Manager (Server-side Tagging & Data Stream Design), event tracking and tagging
• Advertising & Attribution: Google Ads, Google DoubleClick / Campaign Manager, Meta Pixel, affiliate partner integrations
• Experience & Personalisation: Adobe Experience Manager (AEM), Adobe Target, Adobe Experience Platform (AEP), Adobe Edge Network
• Security & Delivery: Cloudflare (CDN), PayPal FraudNet
• Compliance & Governance: OneTrust CMP, consent categories, cookie governance, TDDDG-compliant banner logic
• General web/app services: partner APIs, data transfers, tracking schemas, consent-dependent data activation

• Further development of a complex laboratory information system
• Development of new features including design
• Close collaboration with company leadership
• Embedded in a top team with consistently high performance under time pressure
• Agile approach, Kanban

• Working with developers, security, and operations teams to align requirements
• Supporting product owners and development teams in using logging and monitoring solutions based on the Elastic Stack
• Developing and standardizing log schemas as well as defining practical standards for observability
• Designing and further developing logging architectures for complex, distributed multi-tenant environments
• Connecting application and infrastructure logs as well as security tools and metrics
• Optimizing data flows and modeling for analysis and reporting purposes
• Building automated infrastructures using Terraform/Terragrunt and Ansible
• Maintaining and further developing CI/CD pipelines in GitLab as well as automated development environments in Hetzner Robot
• Operating and automating Proxmox clusters including Ceph storage
• Setting up and operating Kubernetes (k3s) clusters on Fedora CoreOS including base services such as Vault, OpenLDAP, and HA Proxy
• Implementing security-critical infrastructures according to BSI baseline protection and securing existing systems
• Supporting the operation of solutions in cloud environments (including AWS)
• Working in agile teams using Scrum and Kanban
• Technologies/ applications: Elastic Stack (Elasticsearch, Logstash, Beats/Elastic Agent, Kibana), Terraform, Terragrunt, Ansible, GitLab CI/CD, GitOps, Proxmox, Proxmox Ceph, Kubernetes (k3s), OpenShift, Helm, Kustomize, Vault, OpenLDAP, HA Proxy, Hetzner Robot systems, AWS, Prometheus, Grafana, Syslog Linux/Windows, Docker, NGINX, Apache Security & Compliance (BSI baseline protection, SIEM/SOC)

• Role: Developer, Architect
• Technologies: java, typescript, golang, spring (boot, web, security, data), Angular, AWS (OpenSearch, Aurora, SNS/SQS, CloudWatch, EC2, IAM), Kubernetes, Terraform, Helm, OAuth, Keycloak, CI/CD, gradlew, Liquibase, Test Driven Development, shell scripting

• Responsible for the new development of billing and auditing software for prescriptions (prescriptions) to fully check and evaluate e-prescriptions for correctness (content, billing)

• The system consists of several contexts that run as services (Docker containers):

• Checking and processing data deliveries via FTP and email

• Managing invoices, clearings, advance payments and deductions

• Managing and running audit rules and audit folders

• Evaluations based on Metabase

• Developer Stack: Kotlin, Vue 3 / Vuetify 3, ANTLR, Spring Boot 3, REST API, Gradle, Docker, GitLab, PostgreSQL, Kafka, Keycloak, Scrum, Grafana, Loki, Testcontainers, Prometheus

• Analyze and select system components for the web front end

• Create an IT concept

• Consolidate the database in the backend

• Implement the web application with HCL Domino Leap

• Coordinate the setup of two-factor authentication

• Testing and deployment

• Using the low-code development environment HCL Domino Leap, a working web application was developed in a short time.

• The read permission concept was supported without additional coding.

• Authentication for the web application was implemented using OAuth and Google Authenticator.

• Extended the document management system with a standard CMIS (Content Management Interoperability Services) interface
• Implemented CMIS core services like navigation, access rights, search, CRUD operations, and versioning in Java
• Implemented based on RESTful / OpenAPI services
• Delivered as a fat-jar and native container image
• Deployed on-premises and serverlessly as an Azure Container Application using Terraform
• Improved team autonomy through infrastructure engineering and short feedback loops
• Established observability with OpenTelemetry, Azure Monitor, and Azure Logic Apps
• Introduced Terraform and trunk-based development processes
• Ensured quality with BDD tests in C# using SpecFlow and Testcontainers
• Created Azure DevOps pipeline integration tests
• Introduced cloud deployment processes
• Trained staff in cloud and Terraform

• Oversee the development process and review code to ensure quality and adherence to technical standards using Java 17, Spring Boot, Graph API, Spring Core, Spring MVC, Spring AOP, Spring Security, JPA, PostgreSQL, REST
• Engage with clients to understand technical requirements and translate them into actionable tasks for the development team
• Troubleshoot and resolve pre-production and production bugs, conducting analysis, diagnosing issues, and implementing solutions to maintain optimal system performance
• Guide and mentor the Agile development team, providing technical expertise, promoting best practices and coding standards, and fostering a collaborative environment where team members can thrive
• Contribute to overall project planning and customer relationship management to deliver high-quality software solutions

• Manage and operate the product data import services for the Otto merchant
• Enhance and maintain the backend systems
• Optimize and maintain AWS infrastructure
• Build a new product data import API
• Design and plan stories and features
• Conduct code reviews to ensure code quality and best practices
• Analyze and fix bugs
• Technologies: Java, Spring Boot, Kafka, AWS, Fargate, Terraform, MongoDB, Mongo Atlas, OpenAPI, GitHub, GitHub Actions, GitHub Copilot, Akhq, Debezium, JUnit, Test Containers, Hexagonal Architecture

• Electronic logbook app developed for research centers to maintain their investigations.
• Emphasizes user-driven organization of communication: experiment groups can configure information structure and notifications, while principal investigators maintain full access control.
• Real-time integration with the facility’s metadata catalogue, control system Karabo, and data analysis tool enables the automatic logging of key events, complemented by manual entries as needed.

• Lead Drupal 10 developer for several greenfield projects in the health sector
• Drupal architecture in a cloud environment
• Set up and maintain GitLab pipelines and Kustomize scripts for Kubernetes deployments
• Development of Docker images
• Developed custom Drupal modules for features such as OAuth and FHIR
• Drupal frontend theming using Bootstrap 5 and Single Directory Components
• Set up and maintain automated Playwright tests

• Operation and further development of the inventory system for booksellers (Quimus). It is an in-house development by Libri that is sold to customers as Software as a Service. The software is developed in an agile way by two developer teams (about 5 developers each). The software consists of around 25 Java microservices that mainly communicate via messaging and share a common Angular frontend. The application runs on Kubernetes in AWS.
• Technologies used: Java 17 & 21, Spring Boot 2 & 3, Hibernate, MySQL, Spring Cloud AWS, Lombok, AWS SQS, AWS SNS, AWS RDS, AWS S3, DynamoDB, Kubernetes, Docker, OpenSearch, Hibernate Search, Liquibase, Gradle, Terraform, Helm, GitLab CI, Keycloak OAuth2, TypeScript, Angular
• My focus until December 2023: Connecting additional POS systems to the inventory system. Connecting the data warehouse for report display. Extending existing features (goods receipts, invoicing, item management, ...). Operations and DevOps tasks.
• Focus from January 2024: Extracting the product search from the inventory system into a global service to use in other applications. Integrating the product search into the booksellers' online shops (also run by Libri). Importing and providing digital items in the product search.