Senior Software Ingenieur Lead

Started as a Senior Engineer Lead and progressively took over technical leadership of the passenger counting system (VDV-457 compliant, microservices, Spring Boot, Kafka, Kubernetes). Ultimately, as Head of Production, drove the company’s digital transformation through agile practices, CI/CD processes, and modern container orchestration.

• [1] Product-Owner/Solution Architect
  In my role as technical lead, I developed a backend system to standardize data processing workflows on the client side. The aim was to integrate schedule, dispatching, and passenger counting data into a unified structure to enable reliable evaluations and informed operational decisions. At the core of this solution was a solid data analysis, which formed the basis for both the conceptual and technical implementation.
  
  A key element involved the analysis of large datasets, including the collection, structuring, and cleansing of historical data using a PostgreSQL database. For quality assurance, data outliers were systematically identified, and results were visualized through Grafana dashboards. The insights gained directly supported product development and informed client consultations. In addition, the quality of counting data was validated through onboard comparison counts to guide the deployment of sensors.
  
  In parallel, a unified architecture was designed and implemented for various passenger counting systems (e.g., Dilax, Interautomation, IRIS, Dervois/Hydra-IP), along with a scalable solution for displaying live occupancy data within the ETC@DatNet platform. The certification program conducted by IVV GmbH & Co. KG (based on VDV Guideline 457) provided an additional framework for assessing the quality and reliability of the developed system.
  
  Technologically, the solution was based on a modern microservice architecture incorporating SpringBoot, Traefik, Docker Swarm, Kubernetes, Kafka, GitLab CI/CD, and Artifactory. Several system components were implemented, including a VDV-457-compliant web service to provide schedule, real-time, and dispatching data integrated into DatNet@ETC.
  
  Various passenger data formats (file-based, FTP, WebService/XML, WebSockets, JSON-RPC) were standardized and made available through dedicated SpringBoot services. A harmonized data model enabled the centralized storage of all count data in a unified database. Furthermore, a SpringBoot-based service was developed for the saldation (balancing) of count data and its feedback into the system. A user interface was built using SpringBoot MVC, Thymeleaf, Bootstrap, and Charts.js to transparently visualize the saldation algorithm.
  
  For reporting purposes, an imputation method was implemented to close data gaps and ensure VDV-457-compliant downstream processing. The integration of occupancy data into ETC@DatNet enabled live visualization in operations. Dispatching data from third-party systems was connected via SpringBoot web services (including SOAP) and processed through Kafka within DatNet@Dispomanager. The results were finally incorporated into a Power BI business reporting environment to enable well-founded analyses of system utilization and data quality.
• [2] Head of Development
  At the beginning of 2020, responsibility was assumed for leading the Production department, with the goal of actively shaping the company’s transformation into a modern digital service provider. This role was defined by a precise, structured, and sustainable approach that earned wide recognition from both team members and senior management. Even under challenging conditions, stable successes were achieved, and meaningful progress was made.
  
  A core focus was placed on building and further developing self-organized development teams—comprising approximately 25 employees across five teams—by introducing agile methods such as daily standups, retrospectives, and continuous backlog prioritization. The introduction of dedicated Product Owners significantly improved the translation of business topics into technical tasks and brought clarity to planning processes. Development cycles were organized through short sprints and reviewed regularly in close coordination with stakeholders.
  
  To ensure software quality, a unified mindset for managing development states in Jira was established, ensuring clear differentiation between “In Progress” and “Closed” statuses. Technical and organizational measures—such as SLA-based escalation mechanisms, close integration between support and development teams, and the introduction of root-cause analysis tools—led to measurable improvements in operations. During the COVID-related remote work phase, processes were successfully adapted using collaborative tools such as Teams and chat platforms.
  
  The modernization of software processes was driven forward through close collaboration with stakeholders. This included initiatives in software dependency management (Gradle), containerization (Docker, Docker Swarm), identity management (Keycloak), messaging (Kafka), and database versioning (Flyway, Liquibase). A harmonized release management process was introduced to streamline software versioning and deployment workflows. In addition, a Kubernetes-based runbook system was implemented to safeguard recovery procedures and ensure service availability. Quality assurance was supported through automated integration and UI testing (Selenium).
  
  Beginning in 2021, strategic guardrails were introduced to further scale and align production processes. These included aligning teams with market-relevant clusters (Vehicle, Planning, Information, Analysis), bundling sprint increments into modular deliverables, and embedding engineering activities more directly in the offering phase to promote entrepreneurial thinking. Furthermore, cross-functional collaboration with Finance, Sales, and Marketing was strengthened to enhance organizational transparency and effectiveness.

Senior Software Engineer

Contributed to various Scrum teams with a focus on implementation, documentation, coordination, code reviews, refactoring, and analysis. Maintained and enhanced a development platform for an automotive aftersales application, ensuring its evolution and enabling the migration of existing and new microservices to a cloud environment. Developed a master data application in the Connected Car domain to manage and provide access to user, vehicle, and service data. Also responsible for developing and maintaining business workflows using the INUBIT Suite and integrating the Car2Go API with OAuth2.

• [1] Agile Collaboration & SCRUM
  I have worked in agile SCRUM teams for many years, taking on various roles such as Developer, Product Owner, or Story Owner depending on the project. I actively participate in retrospectives, planning meetings, refinements, and daily standups. I foster collaborative work through pair programming and code reviews. For team communication and coordination, I use tools like Jira, Confluence, Slack, Hipchat, and SOCOCO as part of distributed or hybrid teams.
• [2] Microservices & Modern Software Architecture
  I have developed and maintained numerous microservices using Java, Node.js, TypeScript, and Angular. I apply principles of loose coupling, domain-driven design, and RESTful APIs. For data exchange, I work with JSON, MQ, SOAP, and HTTP protocols. My implementations are based on technologies such as CDI, JPA, EJB, and frameworks like Spring Boot, OpenJPA, and DB2/SQL. I focus on building architectures that are scalable, modular, and easy to maintain.
• [3] Software Testing & Quality Assurance
  Ensuring quality through automated testing is an integral part of my development process. I work extensively with TestNG, Mockito, Karma, and consumer-driven contract testing using PACT and the PACT-Broker. I implement unit tests, integration tests, and contract tests for service-oriented architectures. These tests are integrated into CI/CD pipelines to enable stable, regression-proof builds at every stage of development.
• [4] Continuous Integration & Delivery (CI/CD)
  I have extensive experience working in environments with fully automated CI/CD pipelines. Using tools like Jenkins, GitLab CI, Git, Git Extensions, and GitKraken, I manage version control and build automation. I configure Jenkins jobs, monitor builds, execute automated tests, and ensure release quality. I maintain and enhance CI/CD pipelines regularly to support a stable and efficient development lifecycle.
• [5] Cloud Technologies & Platforms
  I have actively worked with modern cloud technologies in several projects, particularly with Docker, Kubernetes, Nexus, and Pivotal Cloud Foundry. I was involved in containerizing applications and successfully deploying them in cloud environments. Using Jenkins and GitLab CI/CD, I automated build and deployment pipelines for production environments. By combining infrastructure-as-code with container orchestration and platform services, I was able to deliver scalable and maintainable cloud-based solutions.

Parental leave

Parental leave on the occasion of the birth of my twins, Toprak and Yağmur

• [1] Consulting, Cine Chromatix KG (10 Month)
• [2] Consulting, Proxel, Berlin Partner GmbH (4 Month)

Senior Software Engineer

At Windhoff Software Services, I worked on a wide range of client projects for well-known companies, focusing on software development, business intelligence, and project management. My responsibilities included managing fixed-price projects with effort estimation, analyzing and optimizing business processes, and designing tailored software architectures. I led development teams, oversaw the integration of BI components into existing systems, and developed business reports using various tools. In addition, I analyzed enterprise data and transformed it into data marts to support data-driven decision-making. The implementation of customized software solutions rounded off my area of responsibility.

• [1] Data Mart Development & Dashboard Design (Oracle, BIRT, Java)
  At Union Investment, I was responsible for the design, implementation, and technical coordination of a business intelligence project. My tasks included project acquisition, effort estimation, project coordination (MS Project), and development of a data mart using Oracle, Toad, and PL/SQL. I evaluated various reporting tools (including Webi, Crystal Reports, Access, BIRT Exchange) and developed a market overview dashboard based on BIRT. The resulting business reports were integrated into the client’s intranet (Java 1.6, JSP, Tomcat, Eclipse).
• [2] CRM Process Analysis & Liferay Integration
  As part of a CRM project at Vodafone D2, I contributed to the integration of Liferay to establish a “Single Point of Access”. I performed process analyses and identified performance bottlenecks in the network using tools such as Wireshark. Additionally, I designed and coordinated a display component for content from the Business Objects Enterprise XI 3.1 platform, collaborating with multiple departments and subcontractors—partially in English-speaking environments.
• [3] Staff Training & Configuration Concept (Business Objects SDK, Java)
  As part of a short-term project at Schenker Deutschland AG, I trained internal staff on the use of the Business Objects SDK (Java JDK 1.6, BO SDK XI Release 2, NetBeans). In addition, I designed a software concept that simplified configuration management and improved maintainability of existing systems.
• [4] Single Sign-On Component Development (Java, JSP, BO SDK)
  As part of an intranet integration project at I.T.E.N.O.S., I was responsible for coordinating, designing, and developing a single sign-on component. The implementation was based on Java Server Pages and the Business Objects SDK XI.
• [5] Controlling Reporting & ERP Integration (Crystal Reports, Epicor)
  For the controlling department of Jung Zeelandia GmbH, I designed and implemented business reports using Crystal Reports. After gathering requirements from key stakeholders, I analyzed the underlying data in SQL Server 2005 and developed tailored reports. The finalized reports were then successfully integrated into the Epicor ERP system.
• [6] Project Lead & Architect for Balancing Software (Industrial Engineering)
  As part of a development project for new balancing software, I conducted a precise analysis of user-specific requirements and documented the software concept using UML (Visio) and MS Office. I facilitated alignment between conflicting goals, defined targets, and assembled a development team that implemented the solution based on my architecture. The technology stack included .NET C# 2.0, Visual Studio 2008, XML/XSD, XMLSpy, Shell scripting, and the Intel Fortran Plugin. I also introduced Subversion and N-Unit testing and was responsible for project management and technical reviews.
• [7] GUI Development for Monitoring Software in the Photovoltaics Sector
  As part of a monitoring software project for photovoltaic systems, I was responsible for designing and implementing graphical user interfaces. The development followed a prototypical approach focused on usability and reusability. The technology stack included .NET 2.0, Visual Studio .NET 2005, C#, and tools such as Cruise Control, NUnit, ReSharper, and Subversion.
• [8] Point of Sale Software Analysis & Reporting (EPOS NT)
  As part of an IT consulting project for Deutsche Post AG, I analyzed business processes related to branch transactions and reviewed large volumes of C# code (.NET 2.0, Visual Studio 2005). I documented the findings using sequence diagrams and internal wiki articles. Furthermore, I developed various business reports (e.g. receipts, invoices) for the branch software using Crystal Reports and provided second-level support.
• [9] Implementation Support for Navigation Software (.NET Compact Framework)
  As part of a project for navigation device development, I implemented specified UI components (interfaces for mobile devices) using C# and the .NET Compact Framework. My work followed a process-oriented approach with code reviews and unit testing. Technical documentation was created using UML models in Together Control Center. Implementation was carried out with Visual Studio .NET 2003 and .NET 2005.
• [10] Development of a Resource Planning Software for Machine Testing
  I contributed to a long-term project involving the redevelopment and extension of a planning software system for machine testing. My responsibilities included process, requirements, and system analysis, as well as business process modeling and system design. I prepared specifications and test concepts, developed an MDI application in Visual Studio, and integrated the solution into SAP and Livelink environments. The technology stack included .NET (1.1 and 2.0), XML/XSD, SQL Server, MS Office, and UML-based modeling tools.
• [11] Reverse Engineering of a Clipper Application and Redevelopment
  As part of a software modernization project, I analyzed an existing DOS-based application (Clipper) through reverse engineering. The goal was to reconstruct the system’s functionality, enable access to dBase tables, and produce functional and technical specifications. I then redeveloped the application using Visual C++ 6.0 (MFC) and implemented PDF-based forms for document output. The new software was successfully integrated into the existing IT environment, including user training sessions.

Software Engineer

At neofonie GmbH, I worked on the development of web portals and middleware systems. I started by implementing online services for a major publishing house in the construction industry and quickly took on independent responsibilities, eventually leading a subproject. In this role, I coordinated development teams, structured tasks, and ensured clear communication. My technical focus was on Java-based middleware components (J2EE, RMI, CORBA, JDBC, JavaMail, JSP) and database development using Oracle PL/SQL.

Later, I contributed to the AOL Germany web portal project, where I analyzed support workflows, integrated Bugzilla, developed an HTTP load testing tool, and implemented JSP-based modules for user and classifieds management. In the “AOL Classifieds” project, I developed editorial approval mechanisms, integrated an XML repository, and implemented an SNMP Java API based on open-source libraries.

• [1] Led a subproject in the development of online services (ibau); coordinated tasks, team communication, delegation and technical guidance
• [2] Developed middleware components using J2EE, RMI, CORBA, JDBC, JavaMail, JSP; database development with Oracle/PLSQL; worked on electronic signature applications
• [2] Performed workflow analysis and integrated Bugzilla for AOL Germany; developed an HTTP load testing tool in Java; implemented JSP-based modules for user and ad management
• [3] Developed editorial approval workflows for AOL classifieds; used Taglibraries, CMS (neofonie ATPS), XML Repository; designed and implemented an SNMP Java API using Jmgnmt

Student Assistant

• [1] Intelligent Networks and Value-Added Services

Student

Degree in Computer Science

• [1] Design and Implementation of a Control Component for Attributed Graph Transformation
• [2] A Visual Modeling Technique for Controlling Graph Transformations
• [3] Information Technology and Law I
• [4] Software Engineering and System Design
• [5] Computer Graphics / Computer Vision
• [6] International Standards in IT and System Architecture I
• [7] Fundamentals of Information Modeling
• [8] Computer Science – Specialization 1 - Databases and Distributed Databases
• [9] Psychological Aspects of Software Ergonomics
• [10] Graph Transformation Project
• [11] Fundamentals of Artificial Intelligence
• [12] Object-Oriented Programming and Modeling
• [13] Bionics I – Laboratory Course
• [14] Innovative Applications II
• [15] Analysis of Computer-Supported Work Activities

Student Assistant

• [1] Development of intelligent agents (Java).