Experience

Open Source Community

• Software Development
• 1 - 100 Employee

• Senior Software Engineer

  • Jun 2002 - Present

  Got into TortoiseSVN development (C++ on Windows) by supplying patches to "scratch an itch" and later became a full committer of that project. Began contributing to the Apache Subversion project (cross-platform C) in 2010 and became a full committer soon after. The "performance expert" within Subversion. Member of the Apache Software Foundation since 2011. Notable contributions to TortoisSVN * Initial port to 64 bit * History data caching (log cache) * Instant, Google-like search even through large amounts of log data * Revision graph rewrite to handle large and complex histories * Seamless integration of user-defined properties as columns into the status dialog Notable contributions to Apache Subversion * Extensive server-side caching schemes, enabling sustained 10Gbps throughput per connection during exports for typical source code projects * Streamlined the svn:// network protocol code to handle 1Gbps of non-file data per connection * Big-O reductions in various places to aid scalability * Significant server-side I/O reduction by improving the physical data layout Show less



WANdisco

• United States
• Software Development
• 100 - 200 Employee

• Subversion Committer

  • Jul 2012 - Oct 2015

  Opportunity to maximize my contribution to Apache Subversion. Fully self-guided and self-motivated work within an open source software community. Development work: * "Performance expert" within the project * Focus: storage backend (repository), request layer and network protocol layer * Goal: high performance even with huge projects and repositories Other: * Public speaking at conferences (SVNlive) * Contact to users and customers Opportunity to maximize my contribution to Apache Subversion. Fully self-guided and self-motivated work within an open source software community. Development work: * "Performance expert" within the project * Focus: storage backend (repository), request layer and network protocol layer * Goal: high performance even with huge projects and repositories Other: * Public speaking at conferences (SVNlive) * Contact to users and customers



Self-employed

• Real Estate
• 1 - 100 Employee

• Senior Consultant

  • May 2011 - Jan 2014

  Going independent to have more time to spend on Apache Subversion development. After being hired by WANdisco as a full-time Subversion committer, fulfilment of existing contractual obligations. Projects: * Consultant in a AUTOSAR tool development * Conception and development lead for a custom subversion client (team of 4 additional developers, globally distributed) * Conception, deployment and programming of required management tools for a globally replicated Subversion setup, including backup and restore as well as automatic recovery after network issues. Show less



ETAS

• Germany
• Software Development
• 700 & Above Employee

• System Architect

  • Jan 2007 - Mar 2012

  Interface and "communication channel" between various ETAS product classes and departments, particularly between software and hardware development. Definition of interfaces and general product architectures to address new whole-system level requirements.Improving architectural design proposals for the product classes that I was responsible for. From time to time, helping with the implementation of critical aspects.Regular contributor to and presenter at the quarterly BOSCH SWAXX (SoftWare Architecture eXperience eXchange).Projects and product responsibilities:* INTECRIO. Focus on cross-product requirements and re-use.* BOA. Basic Open API between ETAS or 3rd party hardware (e.g. connecting to in-vehicle bus systems) and ETAS PC Software. Also helped with the implementation of the protocol stack.* ISOLAR / VAP (AUTOSAR authoring tool based on Java/Eclipse). Architecture of the tool chain, coordination of designs, helped with the prototype implementation.* ASCET Tooling. Correction of design and implementation flaws in add-on products.Process improvement:* Definition of the "System Architect" role* Work at KPA configuration management during CMM(I) level 3 certification* Definition of the "review" process. Reviews are not a tribunal but a tool for communication.* Working group "document management". Migration to Subversion. Definition of the respective processes; adaptations in the TortoiseSVN client. Show less

• Software Architect

  • Jan 2004 - Dec 2006

  Continuous development of the INTECRIO product:* Focus on the evolution of the infrastructure and architecture.* New: Multi-threading, transactions on live object graphs and unlimited undo / redo on them.* All provided generically by the infrastructure without impacting application logic nor UI code.* Coaching other team members and supervising their designs.Process improvement:* Company-wide migration to Subversion as the standard SCM tool.* Helped formalizing the "software architect" role within the development process. Show less

• Software Engineer

  • Feb 2000 - Dec 2003

  Continued development of the SPIDER-Software, commercially available as INTECRIO since 2004. C++ on Microsoft Windows, using COM as component technology.Continuous improvement of the software architecture based on the core ideas laid out in my diploma theses. Training of new members as the team grew.Process improvement:* Evaluation of Subversion for source control. Grass roots approach.* Contribution to in CMM level 2 working groups.

• Graduand in Computer Sciences

  • Sep 1999 - Feb 2000

  Project SPIDER: Productizing a tool for distributed automotive software design based on a precursor of the AUTOSAR methodology. A prototype existed but SPIDER was a entirely greenfield code.Contributions:* Complete architectural redesign* Implementation of the internal data management and storage layers* Concept for a secure component exchange between OEM and their suppliers (IP protection)

• Software Developer

  • Jul 1995 - Aug 1999

  First professional software development projects, while at university. Code written for Microsoft Windows in Delphi and C++ Builder. Products, maintained over several years: * Company-wide time tracking tool with extensive reporting * Project management tool (coupled with time tracker) with cost control etc. Later a cornerstone during customer's ISO certification. * Analysis and verification of manual grid measurements (road profiles etc.). Goals: Flexible rule sets, high throughput, efficient storage. Show less