Graphviz Experts in Germany

• Lead programmer, architect and deputy product owner
• Completed transition from zPDV to STEP
• Ensured quality of C++ and Perl sources through automated and manual checks
• Supported resolution of incidents and errors in testing
• Implemented batch for supplementary assignment of payment run numbers
• Implemented batch for distribution of SGB 2 information to the central payment unit
• Supported replacement of Solaris with Linux
• Upgraded gcc from 7.4 to 9.3
• Programmatically generated Makefiles from Borland projects for builds
• Extended funding data with new attribute “Kennzeichen Fahrtkosten Praktikum”
• Programmatically generated XSD and WSDL files from IDL definitions
• Represented the product owner when needed
• Implemented batch for one-time payment processing
• Developed generator for Liquibase files
• Implemented and maintained regular anonymization of production data
• Supported migration from SLES 12 to SLES 15
• Supported introduction of mutual TLS
• Implemented batch for sending deletion impulses to EDA BE
• Organized script directory structure
• Investigated potential introduction of String-Latin and implemented minimal solution
• Remediated security findings identified by CheckMarx
• Supported PAP recalculations and general change notices
• Converted ERP interfaces from SOAP to REST
• Planned technical and business topics such as register modernization, cash register security, training costs, four-eyes principle

• Develop hardware drivers and middleware using C++11, Java and Python
• Design of various RF features such as deembedding based on stakeholder requests
• Work with multiple teams to design drivers for multiple RF products
• Perform HW control to deliver RF signals and measure modulated response
• Develop RF drivers for generation of low noise signals to test WiFi7 products
• Use digital modulation techniques such as QAM for low level driver development
• Develop low level USB drivers for device enumeration
• Develop drivers for HW relay control of control boards for device testing
• Perform JTAG operations on devices under test
• Use network-based protocols (SFTP, UFTP, FTP, SSH) for control board communication
• Manage HW devices such as BADC and EEPROM for control board maintenance
• Utilize C++11/14/17 features, template metaprogramming and STL
• Employ multithreading for testing and control of multiple HW devices
• Develop tools for deployment of customer OS on control boards
• Perform component and integration tests using CxxTest
• Follow Scaled Agile Framework for software development
• Create detailed design documents using PlantUML

I implemented a Zero-Trust architecture for robust, military-grade maritime container mini data centers based on VMware & Tanzu to support containerized GIS workloads for ground forces. The main focus was on securing communications, workload protection, and data access in contested electronic battle environments affected by jamming, interception, signal manipulation, and constantly changing operational conditions. I designed and architected use cases so that every element of workload, identity, and system could continue to operate independently and securely even in degraded or disrupted scenarios. In parallel, I defined the enterprise and solution security architecture with LeanIX, Bizzdesign, and HOPEX as enterprise architecture, repository, and governance platforms to maintain architecture inventory, relationships, traceability, target pictures, and security governance in complex environments. For the architectural designs, I used Sparx Enterprise Architect to describe formal architecture views, interfaces, trust boundaries, and system architecture in both IT and OT environments. IriusRisk was used for threat modeling of the solution to identify architecture-driven risks, derive security requirements, and detect countermeasures and design gaps directly from the solution models. Risk and compliance management was supported with Archer. Architecture decisions, control gaps, and operational risks were translated into controlled governance and auditable compliance measures. For documentation, collaboration, and visual design, I used Confluence to maintain Architecture Decision Records, Security Blueprints, and workflows. I used Lucidchart and draw.io to create design artifacts tailored to stakeholders. I also defined OT security concepts with support from electrical and mechanical engineers in the areas of oil, vehicle onboard systems, rail, power plants, pharma, gas turbines, and nuclear technology. I created the end-to-end OT security strategy, starting with global policy, developed into standards and procedures, and finally aligned with Bell-LaPadula, Purdue Model, SABSA, TOGAF ADM, CENELEC 50701, IEC 62443, and NIST standards. In addition, I worked with engineering team leads to identify critical KBP assets and place them under protective measures that segmented SCADA, PLC, and HMI assets. I drove collaboration between Security, IT, and OT teams to create standardized workflows and use cases for the OT security solution catalog, while integrating Defense-in-Depth and Zero-Trust principles into operational environments. A key part of my work was integrating multidisciplinary engineering, security, and operations stakeholders into a unified security blueprinting strategy and ensuring that architecture, threat modeling, governance, and documentation were technically strong and operationally practical.

• Database administration and performance tuning for Oracle databases on AIX 7.1, 7.2 with Oracle 12c and 19c
• Troubleshooting and resolution on RHEL 7
• Automation of operations with UNIX/Linux shell scripts, Perl programs, and PL/SQL
• Planning, preparation, execution, and customer-specific review of changes and upgrades for the LEASMAN and DOXIS applications
• Incident handling including communication with outsourcing service providers and business units
• Data exchange with Data Pump
• Visualization of database content and monitoring results
• Configuration of databases for Debezium and monitoring Debezium activities
• Preparation of Oracle databases for migration to cloud environments
• Implementation and monitoring of NIST requirements in databases
• Automation of release upgrades for the LEASMAN application
• Creation of operations manuals and instructions
• Generation of reports for GDPR information requests