• Responsible for infrastructure and application setup and maintenance • Created and extended setup scripts using Ansible, Python, Shell script and Java • Configured and automated BigIP F5 load balancer operations using Ansible • Responsible for Middleware configurations for web and application servers (nginx, Apache httpd, Tomcat, JBoss 6/7 ) • Provided on-call support for releases and production problems • Introduced a template based configuration management using HashiCorp Consul • Planned and performed annual disaster recovery tests • Automated builds for rpm packages including providing them in Satellite / Spacewalk • Configured monitoring using Prometheus and Grafana (for visualization) using different metrics exporters • Created and maintained tooling using Python, Java, Shell script • Managed security configurations including TLS certificates • Started migration from legacy application setup to Docker

• Wrote several Maven and Jenkins Plugins using Java • Migrated build scripts from Apache Ant / Ivy to Maven • Migrated version control system from Harvest SCM to Git (Stash / Bitbucket) and Subversion • Introduced Jenkins for builds and wrote pipeline build scripts using Groovy and Shell script • Wrote and extended tooling using PHP, Perl, Python, Shell script, Ruby and Groovy • Implemented a wrapper for scoring models for the data warehouse team using C, PL/SQL and the Oracle Call Interface (OCI) for Oracle 12 c • Introduced Nexus 2 and 3 for build artifacts and docker images and Sonarqube Sonar for static code analysis • Analyzed and partly fixed build breakers using Java and C • Was responsible for technical release cycle (testing / production build) • Created docker image builds using docker-maven-plugin

• Designed and implemented a stock portfolio optimization web app based on Angular 8 • Extended and optimized the back end interfaces based on Gnu R and MongoDB • Implemented an authorization system with Groovy and Grails and MongoDB • Implemented a template based landing page system with Ruby on Rails and MongoDB • Implemented a ‘portfolio optimizer’ in C using Boost Libraries • Implemented a social trading platform connection interface in C#, SignalR and MongoDB running on a Raspberry Pi • Created numerous tooling scripts in Ruby, Gnu R, Python, Shell script • Created a stock tick database based on Clickhouse including Python tooling for feeding stock data • Did the setup and administration of the web and back end servers running on Ubuntu Linux using Ansible, Apache HTTP Server, Tomcat, MongoDB, PostgreSQL, MySQL • Did setup a third-party web site (https://talk.dresdneralumni.de) using Wordpress including plugin development for special user profiles and activity widgets in PHP

• Extended and bug fixed a stock portfolio optimization portal based on Ruby on Rails and PostgreSQL • Created and modified tooling based on Ruby and Java for stock and portfolio imports • Implemented portfolio optimizing algorithms with Gnu R • Designed and implemented a stock tick database based on Hadoop and HBase • Created a Gnu R / Java Connector for HBase stock data feeder / data query

• Created, optimized and extended the Ruby on Rails based build and release server • Created, optimized and extended Ruby and Apache Ant / Ivy based build scripts • Used Scrum as agile development method

Version control system replacement preparation from CVS to Subversion including Maven2 Java build plugins and tools.Evaluation of several version control systems to replace the old CVS system and introducing the new system. After testing several systems i.e. Mercurial, Git and Subversion, the decision for Subversion 1.5 was made to make advantage of the new merging and merge tracking mechanisms. My work there includes choosing the candidates, creation of test scenarios, balance sheets, presentations, test conversions etc.After the decision was made to use Subversion, I did CVS to SVN conversions with several test cases using Python and shell scripts (as the repositories are huge multiple modules, some up to 5 Gbyte per module), setup and testing of master / slave scalable environment, tooling tests ( Maven 2 SCM, Hudson CI, IDE's, Fisheye, Jira, VCS browsing tools), created trigger scripts for mirroring, commit checks, logging with Python. Checking of access control mechanisms (LDAP, Basic, Crowd) and patching/ extending tools for the ACL like SVNControl. As the build system consists of several specific Maven 2 plugins, I had to change, extend and create several Maven plugins with Java to work with CVS and SVN transparently and be used in the Hudson continuous integration system.The project includes the creation of extensive documentations, presentations, courses use the new SVN system for development and introduce the first modules.Work and development is done under Ubuntu Linux and some specific work on windows XP. IDE's are Eclipse and Netbeans, build systems Maven 2 and Ant. Used programming languages Java, Python, Ruby, Perl and Shell scripting. Version control systems CVS, SVN 1.5, Mercurial, Git.

Extending, optimizing and restructuring the lottery platform www.lottalio.com.Developing and normalizing the existing mySQL database, developing the platform based on Ruby on Rails. Implementation of migration steps, data conversion, introducing transactions for data handling, optimizing and shortening existing methods, adding new features and developing unit and functional tests. Changing and adding cron scripts (Ruby), support for multipart emails and changing external (SOAP based) interfaces to payment providers using Java and Ruby. Web interface development included some minor CSS as well as Javascript (JQuery) development.During the project I was also acting as a Ruby / Rails, database and subversion consultant, created coding and documentation guidelines, release and fallback scenarios, testing and development plans, did several deployment/release cycles and upgraded the system to Rails 2.0.2.Development was done under Windows XP with Netbeans, the version control system was Subversion.

Implementation of a prototype for an 'bonus platform' to integrate into their website. This included the extending of Coremedia CMS for the needed types, implementation of controllers with Struts, Spring Beans, Java Server Pages, Servlets, Servlet filters and listeners for session handling. Another sub-project was the extension of a login system via SOAP calls based on Apache Axis. Final step was the creation of a work and result documentation, integration into the test platform and importing test data in Coremedia.The development was done using IntelliJ under Ubuntu, version control was CVS. The build environment was Maven 2 and Ant. Servlet container was Tomcat 5.5.

Concept and implementation of a room reservation platform for IdealTouristHome. This includes the database planning and creation based on PostgresQL, developing the platform with Ruby on Rails and some Rails plug ins. Some AJAX based functionality was realized with RJS, Prototype and Scriptaculous helper libraries. The database programming included also functions and triggers with PL/SQL. Additionally I did the setup, installation, administration and maintenance of the server, the version control system (Subversion), Mongrel, PostgresQL, Apache and Capistrano for the deployment.

For the music software company Native Instruments I programmed extensions, did performance improvements and added new functionality to their existing customer and software registration system based on Zope and PostgresQL. The programming involved complex SQL queries, trigger and database function programming, XML-RPC on Zope, Python and DTML as well as technical consultant work and creating technical and functional documentations.Development was almost completely done via telecommuting. After the main project time was finished, I worked on some more minor modifications and extensions for their Python / PostgresQL based newsletter server and did some other optimizations.