Amazon Aurora Experts in Germany

• Developed backend features for Modern RIS, a web-based Radiology Information System integrated with the existing Classic RIS via WebView.
• Worked on a modular Spring Boot backend covering clinical workflows such as appointments, examinations, patients, orders, reporting, billing, and inventory.
• Contributed to event-driven architecture using domain events to decouple workflows across backend modules.
• Implemented REST/OpenAPI endpoints, service-layer business logic, DTO mapping, validation, and integration points for the React frontend.
• Worked with PostgreSQL-backed domain models, Liquibase database changes, read/write model separation, and legacy RIS database structures.
• Integrated authentication and authorization flows using Keycloak and OAuth2.
• Added and maintained unit/integration tests using JUnit, Rest Assured, Testcontainers, and project-specific test utilities.
• Supported CI/CD and local development workflows using Maven, Docker Compose, Jenkins, and generated OpenAPI clients.

Tech stack: Java 21, Spring Boot 3.5, Maven, PostgreSQL, Liquibase, Keycloak, OAuth2, REST, OpenAPI/Springdoc, MapStruct, Lombok, Docker, Testcontainers, Jenkins.

Design and implementation of a compact ERP, CRM, accounting, and production-planning platform for a German food manufacturer. The system replaces Rechnung11, self-built Excel sheets, and manual processes for fewer than 10 internal users.

• Designed and implemented the full platform architecture as sole architect and developer.
• Built modules for customer management, B2B order handling, invoicing, production planning, and accounting support.
• Implemented DATEV export, ZUGFeRD/XRechnung e-invoicing, FinTS bank statement synchronization, and GoBD audit trail concepts.
• Used AI-supported workflows for prototyping, test support, and implementation acceleration while retaining full architecture, review, testing strategy, and technical ownership.

Technology: Java 23, Spring Boot 3, Spring Data JPA, Spring Security, Vue 3, TypeScript, PostgreSQL, Flyway, REST, OpenAPI, JWT, TOTP, RBAC, DATEV, FinTS, ZUGFeRD, XRechnung, GoBD, JUnit, Mockito, Testcontainers, Playwright, Docker, GitLab CI/CD

• Designing new apps as well as enhancing and running 29 Angular apps for digital claims in an Nx monorepo
• Maintaining and improving a shared component library with ~300 libraries for multiple product teams
• Migrating all apps to a new design system including its component library and systematic refactoring
• Developing and maintaining the CI/CD pipelines (Jenkins, Azure DevOps, Terraform, AWS)
• Managing releases independently including branch handling, versioning, PR coordination and production deployment
• Implementing and maintaining tracking (Adobe Analytics)
• Ensuring accessibility according to BFSG/WCAG
• Test-driven development (TDD) with Jest and Cypress
• Code reviews, mentoring and setting up best practices in the team
• Technologies: TypeScript, Angular 16-20, RxJS, NgRx, Nx (Monorepo), npm, HTML, (S)CSS, Storybook, Jest, Cypress, Cucumber, Husky, Node.js, Git, AWS, Azure DevOps (Repos & Pipelines), Jenkins, Terraform, TDD, BFSG, WCAG, Nexus, IntelliJ, Adobe Analytics

• Built and verified Zynq-7000 (Zybo Z7-10) FPGA prototypes in Xilinx Vivado – AXI IP integration, bitstream generation, hardware bring-up, timing-closure checks and waveform-based debug to confirm expected RTL behaviour.
• Set up Cadence Virtuoso schematic/simulation flows and documented settings, results and methodology for reproducible experiments – supporting structured verification and research documentation.
• Wrote Python automation for log parsing, structured data reporting and result analysis; worked daily in version-controlled Linux/Git workflows.

Conceptual design and implementation of a modular customer portal based on Laravel.

The focus was on defining a maintainable system architecture with broad use of Domain-Driven Design principles (within the Laravel architecture), introducing automated quality assurance processes (test strategy, CI integration), and preparing an auditable operation (logging, traceability of changes) in an AWS-based infrastructure, taking IT security standards according to NIST and process requirements according to ISO 9001 into account.

Achievements:

• Analysis and structuring of business requirements in close coordination with stakeholders
• Documentation of the system architecture and infrastructure incl. change and release management
• Design and implementation of an interface for integrating SAP systems
• Planning and implementation of automated tests for quality assurance
• Implementation of security and compliance requirements, including SBOM generation, software license management, and QA processes
• Technical consulting and support for the internal IT team
• Introduction and establishment of AI-supported development processes (Spec-Driven Development), including AI-readable specifications, integration of AI instructions into the development environment, and training developers for productive use

Technologies and tools: SAP, Docker, ddev, PHP 8.4, Laravel, Filament, C4 Model, Architecture Decision Records (ADR), Mermaid, PlantUML, Spec-Driven Development, Claude, GitHub Copilot, Codex

• Responsible for Openshift/Kubernetes on-prem administration and developer support.
• Developed URP infrastructure automation with Python, Ansible, Kustomize and ArgoCD, Argo Workflow/Events stack.
• Wrote smoke and load tests for URP infrastructure utilizing Python, Kustomize and ApplicationSets.
• Helped to set up and deploy URP infrastructure in Google Cloud, GKE.
• Set up monitoring for URP and ArgoCD stack with Splunk Cloud.
• Performed system administration tasks across RedHat Linux, Kubernetes/Openshift, ArgoCD, GitLab, Bitbucket Enterprise, Kafka and MongoDB.

• Setup and operation of a multi-cluster AWS EKS platform for banking workloads with a unified network and security architecture across 45 AWS accounts.
• Developed and standardized a unified AWS network and security architecture for 45 AWS accounts, enabling consistent governance, connectivity, and compliance for enterprise customer environments.
• Developed and operated a multi-cluster AWS EKS platform to support production workloads, significantly improving scalability, availability, and operational reliability.
• Implemented a GitOps deployment model using ArgoCD and Helm, enabling fully automated, auditable deployments and reducing manual release errors.
• Automated infrastructure provisioning using Terraform and Terragrunt at scale, reducing environment setup time by up to 70% and eliminating configuration drift.
• Established enterprise-grade backup and disaster recovery strategies using Velero and AWS Backup, ensuring reliable multi-cluster recovery and business continuity.
• Introduced Rancher as a self-service Kubernetes platform, accelerating developer onboarding while maintaining centralized security and governance.
• Designed and implemented detailed AWS IAM concepts (roles, policies, trust relationships) to enforce the principle of least privilege for access to accounts, workloads, and CI/CD pipelines.
• Developed AWS Lambda-based pre-provisioning workflows for databases, automating initialization, configuration, and access setup to support secure and consistent application integration.
• Delivered consistent, high-quality results as part of a 5-person AWS Solutions Architecture team, resulting in three consecutive contract renewals.

• 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

• Migrated the Electric Vehicle Charging SaaS App of the EV Division from on-premises and Azure to AWS Cloud, resulting in a hybrid multi-cloud multi-tenant solution
• Developed a streaming data pipeline using AWS MSK for Apache Kafka and implemented an event-driven architecture to ingest and process near real-time data from OCPI-protocol IoT devices
• Implemented multi-tenant strategies including database schema isolation, bridge model for resource sharing, and tenant-based RBAC controls
• Provisioned Kubernetes clusters on AWS EKS with namespaces and RBAC for tenant isolation
• Led migration from on-premises and Azure to AWS using AWS DataSync, Snowball, and Database Migration Service
• Orchestrated collaboration across 5+ systems, vendors, service providers, and on-site teams
• Supported development and maintenance of IT strategy aligned with business requirements
• Managed €40 million infrastructure budget with AWS & Azure cost optimization, achieving 15% savings
• Led 50+ developers to implement advanced database procedures, increasing productivity by 20%
• Spearheaded multi-cloud, multi-tenant infrastructure migration for 30% faster processing times
• Negotiated vendor pricing to reduce payroll/benefits administration costs by 20%
• Developed a two-year infrastructure technology roadmap yielding 25% cost savings
• Tech stack: Kubernetes on AWS EKS, Docker, Kafka/AWS MSK, Terraform, AWS CDK, TypeScript, React, NextJS, Node.js, NestJS, Python, Aurora Serverless, RDS (MySQL, SQL Server), GitHub Actions, Azure DevOps, ArgoCD, AWS Lambda, API Gateway, AWS Security Hub, AWS Database Migration Service, AWS DataSync, AWS Organizations, AWS Control Tower, Odoo, Microsoft Navision, MS Dynamics

• Developed and implemented an operating concept

• Created and executed a migration plan

• Automated administrative tasks in on-premises environments

• Provided 3rd-level support

• Created documentation (Confluence) and managed tasks (Jira) using agile Scrum methods

• Implemented and monitored disaster recovery plans and backup strategy in Azure

• Planned and carried out software and system upgrades

• Advised on selecting and implementing new technologies and tools

• Trained employees on new technologies and processes

• Conducted code reviews to ensure quality and adherence to best practices

• Advised the Product Owner and other stakeholders on developing and refining solution approaches and concepts

• Responsible for the stable operation of a hybrid on-premises/Azure environment in a highly regulated setting (critical infrastructure)

• Worked closely with business units, IT security, and external service providers to align operational and migration concepts

• Designed and executed the migration of central on-premises systems to a hybrid Azure environment (including landing zone, network segmentation, backup, and disaster recovery strategy), establishing the technical foundation for future cloud governance in the KRITIS sector

• Introduced Ansible & AWX to fully automate formerly manual operational documentation

• Result: Replaced over 100 operation manuals, reduced operational effort by 80%, and created a sustainable foundation for scalable operational processes

• Further development of a finance layer for subscription and one-time purchase billing and accounting.
• Technologies: Kotlin, AWS (SQS, S3, ElastiCache, Aurora), React, TypeScript, Coroutines, IntelliJ IDEA, Spring (Boot, Data, WebFlux), JUnit, Testcontainers, Cucumber, Liquibase, PostgreSQL, Webservices (REST), R2DBC, OpenAPI 3, Gradle, GIT, Docker, Netty, GitHub Actions, Jira/Confluence, arc42

• 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

• Contributed to the development of the Rubix editorial system
• Implemented various microservices based on Java, AWS S3, AWS SQS, AWS SNS, and Spring Boot, deployed to AWS ECS and AWS Fargate
• Designed and developed AWS Lambdas using TypeScript
• Used PostgreSQL in an AWS RDS Aurora cluster and AWS DynamoDB
• Implemented continuous deployment with GitLab pipelines
• Built an Infrastructure as Code environment with AWS CDK
• Set up and maintained a monitoring platform using AWS CloudWatch
• Developed various frontend components with Vue.js
• Designed the microservice architecture applying Domain Driven Design and GraphQL interfaces

• Creation of test concepts
• Development of test processes
• Coordination of test case development: stress tests, functional tests, performance tests, high data rate tests, integration tests, etc.
• Hardware testing: FPGA, RF
• Test automation and regression testing
• Ensuring 24/7 operation of the test system
• Analysis & reporting
• Regular coordination of the test team, meetings with other stakeholders
• Communication and coordination with stakeholders and project managers