TeamCity Experts in Germany

• Development of scalable backend applications with C#/.NET and Java
• Design and implementation of distributed microservice architectures
• Development and integration of REST APIs for industrial applications
• Development of modern web applications with React, Angular, and TypeScript
• Implementation of MQTT-based communication solutions
• Integration of industrial protocols such as OPC UA and Modbus TCP
• Development of batch, process control, and HMI components
• Containerization and deployment of applications with Docker
• Conducting code reviews and supporting architecture decisions
• Close collaboration with Product Owners, QA, and interdisciplinary teams
• Analysis of business requirements and implementation of technical solutions
• Further development of existing software architectures with a focus on maintainability and performance

Technologies: C#, .NET, ASP.NET Core, Java, C++, React, Angular, TypeScript, Vue.JS, MQTT, OPC UA, Modbus TCP, Docker, GitLab, MariaDB, MySQL, Linux

Maturing their API practices on both a business and technology level. My role covers strategy, architecture, developer advocacy as well as hands-on software engineering, enabling both technical teams and business leadership to adopt and act on API-centric principles effectively. Coincidentally, we also establish GitOps, DX and platform best practices with this project.

Highlights:

• Aligning executives with the initiative by clarifying strategy, replacing misconceptions and myths with facts, clarifying the value of existing assets and enabling informed decision-making
• Formulating a way forward for API Lifecycle Management at OTTO
• Driving platform progress and fostering developer engagement by hands-on engineering work towards strategic goals

API Lifecycle Management, Team Topologies, Organizational Evolution, Regulatory, Platform Advocate, Developer Platform, Communities of Practice, Terraform, Kotlin, Kafka, Kong, WSO2, Apigee, Gravitee, Backstage, AsyncAPI, OpenAPI, API Design, AWS, React, Node.js, TypeScript, Redocly, reactive programming, CDC, Golang, Gin, GitOps, DX (developer experience), stakeholder management, roadmaps, workshops, discovery.

• Building a data integration platform for high, medium, and low voltage assets for contextual analysis of time series with master data from the SCADA control system (IEC 60870 104), INIS, and SAP.
• Responsibility for the architecture and implementation of the solution, as well as sparring partner for the Product Owner.
• Use of Kotlin, Spring Boot, Maven, TimescaleDB, PostgreSQL, liquibase, Elements IoT, Docker, Kubernetes, Grafana, Python, jupyter, and various API gateways.

• Adding/creating test specifications
• Performing regression tests
• Performing release tests
• Analyzing Jira tickets
• Identifying software defects and fixing them with C#

• Further development and operation of a central backend service for providing vehicle inventory for international Mercedes-Benz online shops
• Further development of a reservation service for vehicles as part of the checkout process
• Design and implementation of a highly scalable end-to-end test architecture with a focus on maintainability, reusability, and a high number of automated test cases
• Development of a multi-layer test infrastructure with a strict separation of test logic and access layers
• Development of an initialization and caching architecture to significantly speed up local and CI/CD-based test runs
• Development of an AI-supported review architecture for automated evaluation and quality assurance of end-to-end tests
• Development of a dashboard for consolidated display of a vehicle context across multiple backend systems, including AI-generated summaries and compact case analyses
• Integration and further development of connections to various reservation systems via Apache Kafka and REST
• Design of new microservices and support with architecture decisions
• Risk analysis and design of microservice migrations
• Technologies: Java, Spring, Spring Boot, Gradle, Maven, Apache Kafka, REST, OpenAPI, Swagger, Github, Confluence, CI/CD, Microservices, AI, LLMs

• Led the end-to-end delivery of enterprise full-stack web applications by driving requirement analysis, solution design, frontend and backend development, database design, API integration, code reviews, team coordination, Agile execution, CI/CD deployments, production support, performance optimization, security implementation, and stakeholder collaboration to deliver scalable, high-quality software solutions.

• Drive migration of enterprise authorization platform from Styra DAS to open-source OPA via Skipper (Zalando's Golang-based ingress proxy) integration
• Optimise k8s resources and integrate native Prometheus metrics with OPA
• Migrate from internal monitoring solution to Prometheus CRs + Dash0

Tech Stack: Java/Kotlin, Golang, Python, Spring Boot, AWS, Kubernetes, Docker, OpenTofu, Prometheus, Grafana

• PRISMA project
• Ansible automation
• Windows third-level support for Windows NT, Windows 2000, Windows 2013, Windows 2016, Windows 2019

• Fixing issues in the program logic

• Covering the changes with unit tests

• Analyzing and documenting the data structure of the various applications

• Analyzing and documenting the parameters for configuring the applications

• Analyzing and documenting the measures required to ensure the operation of the applications

• Analyzing and designing the separation of the individual database structures

• Analyzing and estimating the effort for planned extensions

• Analyzing, maintaining and documenting a heterogeneous legacy system landscape for a print media service provider

• Technology: C#, VB.NET, C, Python, Microsoft SQL Server, Visual Studio 2010, JetBrains Rider, Visual Studio Code, arc42, Draw.io, Jira, GitLab

• Ensured 99%+ platform availability across Android, iOS, and web, maintaining zero customer-impact and zero P1 incidents through proactive monitoring and risk mitigation.

• Led Incident, Problem, and Change Management with offshore operations and vendors, driving rapid issue resolution and improving product stability.

• Partnered with QA teams and international OpCos to validate defects, reproduce issues, and enhance product quality using real-time customer insights.

• Managed end-to-end lifecycle activities including platform migrations, infrastructure upgrades, certificate renewals, and integrations (Identity, API, Messaging).

• Established operational excellence and governance by designing service support models, leading Early Life Support (ELS) and post-launch stabilization, delivering KPI reporting, and ensuring seamless transition from project to service management.

• Product: Secure Net - Classic, Converged & Home Wifi Protect

• Product Description: The all-in-one digital security service that helps keep you and your family safe online when using the Vodafone (Mobile and Broadband) network. Get alerts if your personal information shows up anywhere it shouldn't, whilst we find and block malicious content across all your devices using.

• Clients: Vodafone OpCos - Spain, Italy, UK, Ireland, Greece, Turkey, Germany, Portugal, Romania

• Role & Location: Service Manager for Lifecycle and Operations at Düsseldorf, Germany

Worked with/on: ITSM Remedy, Jira, Confluence, Splunk, Dynatrace, Tableau, Mongo DB, Google Analytics, App Follow

• 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.

Working as a QA Engineer within a regulated digital health environment, supporting structured test planning, test analysis, verification evidence and release readiness across mobile and web applications.

Creating, maintaining and executing manual and automated (MAESTRO, Katalon, Cypress) functional, regression and SIT test cases for iOS, Android and web platforms. Performing daily activities using Jira, Xray, Confluence, BrowserStack and staged test environments.

Supporting traceability between requirements, risks, test cases, defects and test results, helping ensure QA evidence is clear, auditable and suitable for regulated software delivery.

Collaborating with development, product, medical, regulatory and business stakeholders to clarify requirements, investigate defects, assess severity and priority, and reduce release risk.

Applying ISTQB, Agile and SAFe testing principles across mobile apps (as mobile medical devices), web platforms, system integration and regulated documentation.

Using AI products and open-source AI tools to support QA activities, including test case design, user story analysis, test data creation, process optimisation and regression coverage estimation.

Further development and modernization of a mature Aspire backend application in the energy utility sector, focusing on new business requirements, testing, legacy code cleanup, and stable backend delivery.

Key Contributions & Results Implemented new business requirements in the context of customer orders, subcontractors, and cross-company backend processes, ensuring consistent workflows across a distributed system landscape. Gradually modernized existing backend components and reduced technical debt through targeted legacy code cleanup, refactoring, and structured code reviews. Improved the testability of business-critical services by expanding automated tests with xUnit, AutoFixture, and clearer validation structures. Supported the further development of workflow automation and integration processes through microservices, messaging, and API-based communication. Took over source code from external companies, systematically assessed code quality, and derived technical improvements for maintainability, stability, and integration. Worked in agile development processes with Jira, Confluence, and Azure DevOps and supported cross-team coordination on architecture, quality, and implementation. Technical Metrics Technologies & Methods C#, .NET, ASP.NET, ASP.NET Core, Aspire, Docker, RabbitMQ, gRPC, REST API, Swagger, Microservices, NServiceBus, AutoMapper, Autofac, xUnit, AutoFixture, FluentValidation, Entity Framework Core, MediatR, Redis, Consul, Serilog, SonarQube, Azure DevOps, Azure Monitor, GitLab, Google Protocol Buffers, IronPDF, Mailjet, Jira, Confluence, Miro, Agile Development, Scrum, Code Reviews, Refactoring, Legacy Code Cleanup, Workflow Automation, Power Grids

• Migrate company software to RHEL10
• Development in Bash, Python, C, Ansible