PayPal Experts in Germany

• Further development of the existing e-commerce platform based on SAP Commerce (Hybris) to meet the growing demands of digital commerce.
• Ensuring the scalability and performance of the backend, so the platform remained stable and efficient even under heavy user load.
• Development and integration of new OCC REST APIs and services for modular extensions and flexible adjustments, to implement new features quickly.
• Optimization of data flows and interfaces, which significantly improved platform efficiency and system performance.
• Ensuring a maintainable and scalable code base by using Clean Code principles, proven design patterns, and a future-proof architecture.
• Reduction of errors through extensive testing with JUnit, Mockito, and load tests with Gatling, supported by the introduction of automated test processes.
• Improved system performance through targeted refactoring measures and efficient database queries, especially to handle peak loads.
• Use of modern cloud and monitoring tools such as Kubernetes, Google Cloud Platform (GCP), and Grafana to ensure a stable and monitored infrastructure.
• Clear improvement in efficiency, scalability, and reliability of the platform, which now meets the demands of a dynamic and growing e-commerce market.

Further development of a software solution for managing audit applications and audit notifications according to §106d SGB V for the Association of Statutory Health Insurance Physicians in Hamburg.

• Developed numerous features, optimised performance, refactored code and analysed errors
• Refactored the development container setup
• Optimised the Gitlab-CI build pipeline
• Introduced improvements to the team workflow

Co-founded a software agency building custom web and cross-platform products. I owned the technical decisions across the whole portfolio and led 12 people, while carrying delivery planning, process and client relationships for 11 clients across 3 industries.

• Technical leadership: owned the technical decisions for the codebase across every project — stack, architecture, code conventions and the tooling the team worked with — and led the developers on how work got built through code reviews, pair programming and mentoring across a team ranging from junior to senior, keeping the codebase coherent as the portfolio and the team grew

• Delivery planning against the financial plan: built the company's financial plan and derived from it the billable hours each developer had to reach per month and the hours each project could absorb to stay within budget; planned capacity and scope against those figures and negotiated budgets and delivery dates directly with clients

• Client ownership: technical contact across the portfolio — requirements gathering and prioritisation, scoping and estimates, timeline communication, budget negotiation, and consistent transparency throughout delivery

• Team and people: owned the hiring and interview process end to end and took responsibility for offboarding where it was needed; designed an onboarding that got new developers productive within 1–2 days; cleared blockers daily and kept a close eye on where effort was creating value and where it was not

• Process ownership: consolidated a micro-service landscape spread over 15+ repositories into a single monorepo, cutting backend development time by ~40% and simplifying releases for 6 engineers; set up deployment pipelines with GitHub Actions and GitLab CI; ran retrospectives and turned the feedback into concrete changes; introduced AI agents into day-to-day development

• Delivered short-staffed: when the team shrank from 8 developers to 2, restructured scope, introduced AI-assisted development to hold the schedule and took on Go backend work alongside my own frontend scope

• Architecture and code: defined the architecture for every project in the portfolio — the structure the rest of the team built within — and wrote roughly 90% of the frontend code myself, from SSR applications with Next.js and Remix to cross-platform apps with Capacitor

• From zero to production: took a practice management platform — administration, inventory, integrated online shop, chat messenger — from an empty repository to production. Live in 7 markets with at least 7 more coming up, serving tens of thousands of users

• Delivery under pressure: built and shipped a replacement online shop for a Fortune 250 client in 4 days, restoring order intake while their global shops had been offline for several weeks

• Design system: built a cross-project design system used across 7 products, so new projects and features started from a shared, consistent base

• Cross-platform and real-time: built iOS and Android apps with Capacitor for a client live event with 1,000+ participants — web sockets and push notifications for real-time content, Stripe payments supporting PayPal, Apple Pay, Google Pay and cards

Key technologies: React, TypeScript, Next.js, Remix, GraphQL, ConnectRPC, Redux, Zustand, Go, Node.js, Turborepo, Nx, Capacitor, Ionic, WebSockets, Stripe, PostgreSQL, Playwright, Cypress, Vitest, Storybook, GitHub Actions, GitLab CI, Claude Code, Cursor, GitHub Copilot

• Worked on an FTTx/telecommunications project within the project environment
• Supported operational project coordination and task follow-up
• Used Jira to create, process and track tasks and tickets
• Structured and maintained project-related information and work statuses
• Coordinated open points and ongoing tasks within the project team
• Supported the coordination of work packages and their processing status
• Followed up on tasks, feedback and open topics
• Worked at the interface between operational implementation and project organization
• Applied digital project management tools in the ongoing FTTx project
• Provided hands-on support with organizational and operational project tasks

• Leadership, management, and further development of an accounting team with nine employees
• Responsibility for the preparation, analysis, and quality assurance of monthly and annual financial statements according to HGB
• Ensuring structured intercompany reconciliation and minimizing reconciliation risks using LucaNet
• Coordination of annual closing work and audit preparation while meeting CFO deadlines
• Optimization of accounting processes in the SAP S/4HANA environment in close

In my role as Senior Cloud DevOps Architect for BP, an oil and gas company, I had the mission to migrate the Electric Vehicle Charging platform of the EV Division from on-premises and Azure to AWS cloud, resulting in a hybrid multi-cloud, multi-tenant SaaS solution.

Deployment with Kubernetes for the application layer meant provisioning Kubernetes clusters managed by EKS and AKS, with a focus on integrating them into a multi-tenant environment. This integration was achieved by using Kubernetes namespaces and access controls to ensure data isolation and privacy enforcement.

In the database layer, we chose an RDS instance with PostgreSQL to support the backend infrastructure of our applications. Tenants shared the same RDS instance, but each had a dedicated schema.

To ingest near real-time data from physical charge points (CPOs), as IoT devices, via the OCPI protocol, we ran into significant delays with batch processing. As a result, we built a real-time streaming data pipeline using Apache Kafka, while prioritizing an event-driven architecture.

Led collaboration across multiple internal teams, external vendors, cloud providers, and on-site partners to integrate over five systems into a unified solution.

Achievements:

• Successfully designed and implemented hybrid multi-cloud solutions, integrating multiple cloud platforms (AWS, Azure) with on-premises infrastructure, using Site-to-Site VPNs, Firewalls, and Load Balancing.
• Led the migration of on-premises infrastructure to multi-cloud, multi-tenant infrastructure, resulting in 30% faster processing times.
• Migrated workloads from VMware and Hyper-V environments to cloud-based VMs, leveraging cloud-native services to optimize performance, cost efficiency, and scalability.
• Designed a multi-tenant Kubernetes platform leveraging the Kubernetes ecosystem, using Karpenter for dynamic EC2 node provisioning, KEDA for event-driven pod autoscaling (e.g., Kafka message lag), and Rancher for centralized monitoring of multiple clusters (EKS, AKS, or on-prem K8s), replacing Microsoft-centric Azure Arc management service.
• Designed and implemented Python-based FastAPI microservices as part of the EV core-backend on AWS EKS application layer, powering data ingestion and customer analytics pipelines.
• Developed asynchronous, event-driven APIs (Python-FastAPI) for real-time integration with CPOs, supporting OCPI 2.3 and OICP protocols.
• Designed and implemented a secure, production-grade Azure Databricks platform using Terraform, ensuring scalability and cost efficiency.
• Migrated on-premises ERP to a hybrid Dynamics 365 architecture with ERP hosted locally and CRM running in Azure, integrated via Azure Arc.
• Automated CI/CD pipelines for Databricks notebooks and jobs using GitHub Actions & Databricks CLI, reducing deployment time. Reduced infrastructure provisioning time by 70% by automating cloud resource deployment with GitOps.
• Ensured compliance with internal audit and data governance standards (GDPR) through OAuth2/OIDC-based authentication and fine-grained role-based access controls.
• Developed a Zero Trust security model, enforcing least-privilege access and microsegmentation, enhancing security posture and compliance with GDPR and NIST.
• Built interactive analytics dashboards in Amazon QuickSight, integrating data from S3 and Redshift to deliver real-time business insights and visualizations with embedded access for multi-tenant users.
• Led cloud security assessments and full-lifecycle cybersecurity integration during M&A, covering AWS, Azure, IAM (Entra ID), and data protection, while aligning security posture with NIST, ISO 27001, and GDPR across hybrid and cloud-native environments.
• Reduced cloud costs by 64% for a client's dev environment by implementing automated start/stop schedules for EC2 and RDS instances via AWS CDK with EventBridge Scheduler or AWS Systems Manager.

Tech stack:

• Infrastructure as Code: Terraform, AWS CDK, Ansible.
• Containers: Kubernetes on EKS, AKS, Docker.
• Streaming Data Processing: Kafka to Confluent Cloud, after AWS MSK.
• Frontend: TypeScript, React, NextJS, Hooks, Styled Components.
• Backend: Python with FastAPI, also Node.js with NestJS.
• Database: Aurora on PostgreSQL with TypeORM, RDS on SQL Server, Azure Databricks full setup and administration, ETL Pipelines.
• CI/CD and GitOps: GitHub Actions, Azure DevOps, ArgoCD.
• Monitoring and Observability: Prometheus and Grafana.
• Virtualization: Hyper-V, VMware Cloud on AWS, Azure Migrate.
• ERP Systems: Odoo, Microsoft Dynamics 365 Business Central on Azure, integrated with Azure Arc.
• Networking: Site-to-Site VPNs, AWS Direct Connect, Azure ExpressRoute, Firewalls (AWS Network Firewall, Azure Firewall).
• Security: IAM, NIST Framework, Zero Trust Security, AWS WAF, AWS Shield, GuardDuty.

(Maternity/Parental Leave: July 2023 – Aug 2024)

• Domain: Payment Domain | Client: Telefonica Germany
• Project: General Payment Service

The General Payment Service is responsible for processing of online payments via external payment service provider like Safer pay and PayPal

• Developed Design of Use (DOU) and interface contract documentation, ensuring clarity and compliance across system integrations
• Designed and delivered REST/SOAP web services with Spring Boot and Spring Data JPA, publishing Swagger contracts through WSO2 API Gateway to improve accessibility and governance.
• Spearheaded the on-premises to AWS Cloud migration, re-platforming from Oracle to PostgreSQL on AWS RDS and deploying services on EC2, improving scalability and cost efficiency.
• Containerized microservices using Docker and orchestrated deployments with Kubernetes, streamlining deployment pipelines and improving system reliability.
• Implemented proactive monitoring and logging via AWS CloudWatch and Kibana, ensuring stability and performance during cutover.
• Enhanced collaboration through code reviews and peer reviews, promoting maintainability and clean coding standards.
• Strengthened quality by writing comprehensive JUnit tests and preparing detailed test cases enabling early defect detection
• Delivered automated API testing with Ready API, Postman, and SOAPUI, and conducted performance testing with JMeter, ensuring reliability in high-transaction environments.

• Design and supervise implementation, testing and rollout of end-to-end processes and system integrations (frontend & backend)
• Integrate with OEMs (Daimler, BMW/MINI) and CPOs (Ionity and others)
• Introduce CPO discount packages with lifecycle processes
• Implement consenting process for GTC & tariff updates and marketing opt-ins via SAP Emarsys
• Automate blocking/unblocking of customers and integrate MS Dynamics CRM and proprietary 3rd level tool
• Coordinate migration and go-live of new fleet portal
• Migrate PSP from Datatrans to Adyen (credit card, PayPal) and integrate SEPA/BACS with Adyen via webhooks
• Support and enhance OpenInformer billing engine: Oracle→PostgreSQL migration, PostgreSQL upgrade, regression test suite, performance troubleshooting, invoice relocation to Azure Storage
• Identify and analyze fraud cases and implement countermeasures
• Provide problem management, incident support and hypercare after major rollouts

• As part of the program (RAITT Transformation/Inlife Tribe), efficient handling of all processes for existing customers during ongoing operations and in customer service, including payments and billing, with the goal of ensuring customer satisfaction through excellent service and efficient problem solving

• Leading the Usage-to-Payments value stream and cross-functional teams as the responsible Epic Owner in the strategic RAITT transformation program

• Managing, prioritizing, providing functional direction and driving decision-making processes between business, architecture, development and outsourcing partners

• Backlog prioritization, strategic roadmap development and release readiness decisions

• Establishing governance, quality assurance and delivery standards in the payment ecosystem

• Communicating program-critical decisions to sponsors, Product Owners and technical control centers

• Ensuring smooth payment processes, accurate billing and integration with financial systems

• Optimizing payment methods, managing payment service providers and efficiently handling credit checks, dunning and debt collection

• Focus on postpaid business models with bank transfers, direct debits, returned direct debits and payouts

• Responsibility for alternative payment methods such as credit cards and PayPal, integration of payment service providers and risk management

• Development of a SaaS platform for esports teams with roles, scheduling, statistics, and billing
• Planning and implementation of the architecture, external API integrations, and operations
• Stack: Laravel 13, React 19, TypeScript, PostgreSQL, Redis, and Stripe

• Interim Product Owner for two new applications as part of the introduction of a new bonus points program within the entire Rewe Group
• Coordination of cross-team planning (initiative management) and implementation
• Responsibility for product vision, roadmap, backlog and stakeholder management within an agile scaled product development team
• Successful Go Live with both applications on 2024-09-24

• Acting as the program lead for digital enabled services overseeing projects like Transformation, remote scanning (WeScan), e-commerce, OneGate (budget: ~5mio€/p.a.).
• Develop the transformational strategy & roadmap for a supply & demand platform on ServiceNow, driving harmonization & integration of legacy systems.
• Led cross-functional teams for design and rollout of these digital business models on ServiceNow backend platform.
• Enabled strategic decision-making by combining Azure DevOps transparency structures including using Agile methods like PI Planning, WSJF priorization.
• Acting as the business demand manager & digital counterpart for CS CRM.
• Responsible for the internal project organization & external partners as well as organizational interfaces & dependencies to other departments.
• RFP execution & manage vendors in accordance with contracts and internal requirements.
• Contributed to Project sucCeSs, Northstar and being part of the RaaS Tiger Team & Spryker Customer Advisory Board.

• Worked as a full-stack developer managing front-end and back-end development with a responsive approach
• Implemented unit testing, functional testing, and code coverage testing
• Followed Scrum, used Agile methodology, and worked with CI/CD processes
• Recruited and trained technical staff
• Assigned tasks and oversaw their execution
• Collaborated with the team to troubleshoot technical issues
• Assessed user requirements and delivered suitable solutions
• Set team goals and monitored progress
• Ensured software and applications were up to date
• Supervised system changes
• Tech stack includes PHP (Symfony, Laravel), Spryker, Node, TypeScript, JavaScript, jQuery, MySQL, etc.