Resume (February 6, 2025)

SUMMARY

SELECT SKILLS

• Languages: German (native), English (fluent: 22 years of English-speaking projects – sample)
• Expert: Java (26 yrs), relational databases (31 yrs), technical writing (25 yrs)
• Specialist: Remote work (12 yrs), specification (16 yrs), test cases (16 yrs), tester (16 yrs), Spring (10 yrs), Spring Boot (7 yrs), Angular (6 yrs), Flutter (5 yrs), SQL (22 yrs), IntelliJ (6 yrs), Jira (7 yrs), Confluence (7 yrs)
• Advanced: SCRUM (3.5 yrs), project manager (14 yrs), product owner (12 yrs), architect (22 yrs), system administrator (14 yrs), Java EE (15 yrs), JavaScript (20 yrs), TypeScript (6 yrs), REST (5 yrs), SNMP (13 yrs), HTML (22 yrs), CSS (22 yrs), MySQL (13 yrs), PostgreSQL (6 yrs), Spring Data (5 yrs), Apache POI (4 yrs), Liquibase (5 yrs), JUnit (5 yrs), Mockito (5 yrs), Tomcat (13 yrs), Docker (5 yrs), Maven (10. yrs), Gradle (6 yrs), Git (6 yrs), Google Firebase (4 yrs), Linux (19 yrs), Rule Engines (4 yrs)
• Knowledgeable: React.js (1 yr), JWT (5 yrs), Kubernetes (2 yrs), AWS S3 (2 yrs), AWS SNS/SQS (2 yrs), Kafka (1 yr), GraphQL (2 yrs), Swagger/OpenAPI (1 yrs), Terraform (2 yrs), MongoDB (2 yrs)

JAVA PROJECTS

Senior Full-Stack Developer Goldbach neXT, Switzerland Jan 2023 – Dec 2024

• New ad booking system as a back-end
• New cross-ad-type booking system with ad catalog and connection to ad-type-specific validation, booking and delivery systems
• Completely in-house developed 14 microservices with REST and GraphQL APIs in AWS Kubernetes and an internal web application
• Apart from me, 1 product owner/SCRUM master, 1 architect, 0-4 developers
• My contributions: coordinated developers, wrote some specifications and most test cases, developed back-end and web application, did code reviews, tested, rolled out releases, provided support
• Project language English, 80% remote work
• Technologies: SCRUM, Java, TypeScript, Spring Boot, MongoDB, PostgreSQL, Spring Data, Kafka, Apache POI, REST, JSON, GraphQL, Swagger/OpenAPI, AWS S3, AWS SNS/SQS, AWS Cognito, AWS Glue, React.js, HTML, CSS, JUnit, Mockito, IntelliJ, Maven, Git, Docker, Terraform, Kubernetes, Sonarcube, GoCD, Argo CD, Custom CI, Elasticsearch, Jira, Confluence, GitHub, Linux

Full-Stack Developer, CTO, Co-Founder Your Home in Good Hands Ltd, UK Since Jan 2020

• New SaaS workforce management system for cat sitter companies
• Completely in-house developed web application for customer and booking management
• Built and updated with Java code generator JHipster (Angular, Spring Boot, PostgreSQL), runs in Docker
• Completely in-house developed native iOS and Android apps (Google Flutter) for cat sitters (in the UK app stores) to prepare and document home visits
• Google Firebase for authentication and files
• My contributions:one-man project - product owner, project manager, architect, developer, tester, write all specifications and test cases, roll out releases, provide support
• Project language English, 100% remote work
• Technologies: Java, TypeScript, Dart, Angular, REST, JSON, HTML, CSS, Flutter, JHipster, Spring Boot, Google Firebase, Spring Data, Apache POI, PMD, SQL, PostgreSQL, Spring Data, Liquibase, Error Prone, SpotBugs, JUnit, Mockito, IntelliJ, Gradle, Git, Docker, Nginx, iOS, Android, Gitlab, Gitlab CI, Jira, Confluence, Linux

Senior Full-Stack Developer aformatik GmbH, Germany Jun 2018 – Jul 2019

• New, internal billing system for IT resources
• Completely in-house developed web application that reads files with usage data and creates invoices for cost centers
• Initially created with Java code generator JHipster (Angular, Spring Boot, PostgreSQL), runs in Docker on mainframe
• Apart from me, 1 product owner/SCRUM master, 2.5 developers
• My contributions: architect, coordinated developers, wrote specifications and test cases, developed, tested, rolled out releases, provided support
• Project language German, 5% remote work
• Technologies: SCRUM, Java, TypeScript, Angular, REST, JSON, HTML, CSS, JHipster, Spring Boot, Hibernate, SQL, PostgreSQL, Spring Data, Liquibase, JUnit, Mockito, IntelliJ, Gradle, Git, Docker, Nginx, Jenkins, Linux, z/OS

Full-Stack Developer PDV-Systeme GmbH, Germany Jun 2017 – Mar 2018

• Distributed print server monitoring system
• Completely in-house developed web application that monitored distributed printing of a document management system for public service
• My contributions: one-man project – project manager, architect, developer, tester, wrote all specifications and all test cases, rolled out releases, provided support
• Project language German, 100% remote work
• Technologies: Java, Java EE, JavaScript, Thymeleaf, HTML, CSS, Spring Boot, Hibernate, Apache Artemis, IntelliJ, Tomcat, Zabbix, Maven, Git, Linux, Windows Server

Senior Full-Stack Developer, CTO, Co-Founder Seldon Systems, US/Germany Jan 2004 – Jan 2017

• Two customer applications for service provider to small and medium-sized cable TV operators
• Completely in-house developed applications replaced existing web application for analysis and configuration of cable modems, email addresses and websites
• Created with Java, Struts, HTML, MySQL and ActiveMQ, runs in Tomcat
• Apart from me, 3-4 developers, 1 analyst/tester
• My contributions: architect, coordinated developers, developed, tested, wrote test cases, rolled out releases, provided support
• New power supply monitoring product for cable TV networks "Continuity-SPS"
• Completely in-house developed product that monitored up to 60 000 power supplies in the cable TV network from one server via SNMP, ran scheduled battery tests, and predicted remaining battery life during power outages
• Achieved 80% market share in North America, had corporate licenses with Comcast and Time Warner Cable and protected TV, Internet and telephone services for 50 million households in North America during power outages
• Built with Java, Spring, Struts, HTML/Adobe Flex and MySQL, ran in Tomcat
• Apart from me, up to 4 developers, 1 analyst, 2 testers, 2 support engineers, 1 VP of Operations
• My contributions: most of the time: product owner, project manager, wrote all specifications; architect, coordinated developers, developed, wrote most test cases, tested, rolled out releases to customer servers, supported support as 2nd level
• New battery and device monitoring product "Continuity-SBL/FAC"
• Completely in-house developed product that monitored and tested batteries, generators, UPS, and rectifiers in data centers, cell towers, cable network headends, and similar facilities through SNMP to prevent failures during power outages
• Built with Java, Spring, Struts, HTML/Adobe Flex and MySQL, ran in Tomcat
• Apart from me, up to 2 developers, 1 analyst, 1 tester, 2 support engineers, 1 VP of Operations
• My contributions: most of the time: product owner, project manager, wrote all specifications; architect, coordinated developers, developed, wrote most test cases, tested, rolled out releases to customer servers, supported support as 2nd level
• New call center software for power supply installers in the cable TV network
• Completely in-house developed call center web application supporting the maintenance and testing work of power supply installers in cable TV networks
• Built with Groovy & Grails, Rule Engine Drools, and MySQL, ran in Tomcat
• My contributions: one-man project – project manager, product owner, architect, developer, tester, wrote all specifications and all test cases, rolled out releases, provided support
• Project language English, 8 of 13 years remote work
• Technologies: Java, Java EE, Groovy, JavaScript, SNMP, Struts, JSP, HTML, CSS, Adobe Flex, Spring, Grails, Apache Lucene, ActiveMQ, Rule Engine Drools, mybatis, Hibernate, SQL, MySQL, Tomcat, Eclipse, Ant, Maven, Bugzilla, Jira, Confluence, CVS, Git, Linux, Windows Server

Full-Stack Developer Kirchhoff Datensysteme Software GmbH, Czech Republic Sep – Dec 2003

• Audit of a car dealer management product
• Software had technical challenges
• My contributions: interviewed stakeholders, suggested project management improvements, defined rules for interface between presentation and business layer, wrote test cases, developed
• Project language English
• Technologies: Java, Java EE, Struts, HTML, CSS, Oracle 9i, Oracle 9 Application Server, Oracle JDeveloper, Ant, CVS, Bugzilla, Windows NT

Full-Stack Developer PDV-Systeme GmbH, Germany Jan – Aug 2003

• Migration of a document management system for public service to Java
• Porting an inhouse-developed Windows desktop application in C++ to a new Java EE web application with Struts, while retaining the data structures in the Oracle 9i database
• Apart from me, 1 CTO, 1 project manager, 1 architect, 20 developers, 5 analysts/testers, 3 administrators
• My contributions: defined Java EE architecture that ran in Oracle 9 Application Server and in servlet containers such as Tomcat, trained developers in Java and Java EE, selected tools, created Ant build system for JDeveloper and terminal, developed, supported troubleshooting
• Project language German
• Technologies: Java, Java EE, JavaScript, Struts, HTML, CSS, Oracle 9i, Oracle 9 Application Server, Oracle JDeveloper, Ant, CVS, Bugzilla, Windows NT

Senior Full-Stack Developer Mundwerk AG, Germany May 2001 – Aug 2002

• New Java voice application platform
• Completely in-house developed platform which processed voice applications according to the VoiceXML standard and made them available by telephone
• Created with Java and JSP (for voice applications), used JSP engine from Tomcat, integrated Nuance software for telephony, speech recognition and text-to-speech
• Apart from me, 6 platform developers (mostly part-time), 2 voice application developers (full-time), 2 audio engineers, 3 linguists/testers (2 part-time), 1 administrator
• My contributions: coordinated platform developers, represented platform at meetings with application development & linguistics, developed, tested, rolled out releases, supported troubleshooting
• Two new voice applications in Java
• Led creation of two customer voice applications: Telekom application for the 2002 Football World Cup and a gas meter reading application for an energy company
• Apart from me, 1 CTO, 6 platform developers (mostly part-time), 2 language application developers (full-time), 2 audio engineers, 3 linguists/testers (2 part-time), 1 administrator
• My contributions: project manager, wrote specifications and test cases, coordinated platform and application developers, represented platform & application at meetings with linguistics, developed, tested, rolled out releases, supported troubleshooting
• Project language German
• Technologies: Java, VoiceXML, JSP, Voice Recognition Nuance, SQL, MySQL, CVS, BSD Unix, Eclipse

Senior Full-Stack Developer AMS Inc, Netherlands Jan 1998 – Sep 1999

• Research project Agents for Negotiation and Trade Services (ANTS)
• Two intelligent agents negotiated a purchase with each other
• Presented in one-day hands-on workshops in six countries across Europe, where participants programmed agents themselves
• Apart from me, 1 expert for agents
• My contributions: project manager, architect, developed, wrote all specifications and test cases, tested everything, wrote workshop documents
• Research project AMSCAT Intelligent Agent Initiative (AI²)
• Intelligent agents negotiated new price plans in mobile telephony systems on behalf of customers
• Collaboration with the Free University of Amsterdam (Multi-Agent Systems, Agent-Based Negotiations)
• Besides me, 3 developer, 2 agent experts
• My contributions: project manager, architect, coordinated developers, wrote specifications and test cases, tested everything
• Project language English
• Technologies: Java, Java EE, JavaScript, Swing, HTML, EJB, XML, RMI, Rule Engine OPSJ, IBM WebSphere, DB2, IBM VisualAge for Java, Windows NT

SPEAKER & AUTHOR

EDUCATION

Computer Science Study Dresden University of Technology, Germany Oct 1990 – Jan 1996

• Master of Computer Science: Final grade "Very Good" (among the top 10% of my peers)
• Major: Software Engineering, Databases
• Minor: English, occupational psychology