• Increase font size
  • Default font size
  • Decrease font size
Home Professional

Resume Volker Kueffel

E-mail Print

Volker Kueffel
2591 20th Avenue, San Francisco, CA 94116
phone: 415 637 2250


Employment history

inPoweredSan Francisco, CA; June 2011-current

Software Architect

  • Re-Architected data platform from a batch oriented conglomerate of PHP scripts to event based scalable system written in Java leveraging mainly Spring and Apache Camel to drive business logic. Implemented multiple of its sub-systems.
  • Used AWS SQS and auto-scaling groups running hundreds of EC2 instances of various types to allow to scale to (currently) 1000x the load of the original system.
  • Built system to collect social media signals for hundreds of millions of articles.
  • Migrated TB-size database from MySQL to DynamoDB using Map/Reduce technologies.
  • Used a wide range of AWS products to reduce DevOps efforts; these include EC2 with ASGs, SQS, RDS, DynamoDB, S3, ElastiCache Redis, SimpleDB, CloudWatch.
  • Leading effort to reduce AWS cost by optimizing EC2 instance types, reservations, utilization and auto-scaling rules as well as reorganizing storage solutions resulting in 25%+ cost savings so far.

Independent contractor, San Francisco, CA; September 2006-June 2011

Software Development and Architecture

  • Click Group, Inc: Redesign of backend of major search engine marketing system, using Symfony PHP web framework. Design and create automated feed system to import large amounts of data; include data retrieval, modification and output generation in various formats; use Gearman to allow for asynchronous processing. Implementation of  client software for Google Adwords API, Yahoo Search Marketing web services, Microsoft Adcenter API, Google Analytics API and creation of automated reports for clients using the data retrieved.
  • Hands-On Mobile/GoTV Networks: Provide backend services for the international version of NFL.com's mobile phone application for which  data feeds - accessible through different channels (HTTP, FTP, Email)  and in different formats - are retrieved, analyzed and imported. XML feeds were analyzed using XPath. Implemented in Java using Spring and Hibernate.  Web services allowed data retrieval by the frontend application. Implemented backend services for  Verizon Wireless NFL Draft mobile phone application using the same technology.
  • Streamworxx: Designed and developed administration and delievery system for internet videos. Written as a Java application using Spring and ActiveMQ as main components video content is stored on Amazon S3 through their SOAP and REST APIs and delievered using Amazon's content delivery network CloudFront.The multilingual frontend is built on ExtJS and Apache Velocity.
  • Signatures Network: Modernized existing PHP framework to meet current object oriented standards. Maintain existing Java application running on WebObjects application server. Implemented SOAP client using Apache Axis to transfer customer information to external marketing service provider.
  • Native Instinct: Designed and developed web based tracking system for major janitorial company using object oriented PHP 5 on the back end and Google's Web ToolKit for dynamic page elements.

WorldRes, San Mateo, CA and Düsseldorf, Germany; December 1999-May 2006

Senior Software Engineer

  • Responsible for gateway to external credit card processors
    • Designed scalable server application processing transactions worth of approximately 2 million USD a month
    • Created Java server application using Apache Tomcat as servlet engine and Apache SOAP to provide standardized internal interface to external credit card processors, handling HTTPS requests to the outside
    • Created monitoring tools written in Perl (SOAP::Lite) to guarantee availability of gateway
  • Designed and developed Java API for hotel booking engine
    • Provided functionality to access and manipulate content and booking information
    • Interface with central repository (JDBC to Sybase Adaptive Server)
    • Created SOAP interface to API using Apache Axis
  • Led development team to create web based administration system for hotel content and rates
    • Designed application and led development
    • Written as object oriented PHP application using nuSOAP to access web services
  • Released applications into production environment and monitored them
    • Used Cricket to graph relevant operational information
    • Troubleshooting of the production system

Telemedia GmbH & Co KG, Gütersloh and Essen, Germany; January 1998-November 1999

Software Engineer and development team lead

  • Created “document management system” using Informix Universal Server
    • Created library of stored procedures and applications based on this library
  • Built website for German Hotel Association using PHP
  • Consulting and development for launch of sports website www.sport1.de
  • Led development team dedicated on the cityweb project (see below)

Cityweb Network GmbH, Essen, Germany; November 1996-December 1997

Software Engineer

  • Designed and developed completely database driven high volume newspaper web sites
    • Created database driven localized websites using Informix web datablade
    • Created templates and administer content management system Red Dot

University of Duisburg, Duisburg, Germany; May 1995-October 1996

Member of scientific staff of Laboratory for Solid State Physics

  • Built ultra thin magnetic layers
    • Built equipment and controlling software to create magnetic layers using high energy lasers
  • Research on electronic transport properties
    • Built equipment and controlling software
    • Research on electronic transport properties of boron compounds


University of Duisburg, Duisburg, Germany
1989-1996 Masters in Physics

IT Skillset

  • Programming languages:
    • Java:
      • 9+ years experience in building enterprise scale client/server applications
      • Experienced in using standard Java technologies and frameworks (Java Beans, JDBC to MySQL, Sybase, Hibernate, Velocity, DBCP, JMS, Spring) and
      • Built Java web service applications using the SOAP protocol (Apache Axis, Apache SOAP)
      • Worked with JMS using ApacheMQ message queue
      • Several years experience with Eclipse IDE
    • Perl (5.6.x and 5.8.x):
      • 6+ years experience building monitoring tools and batch applications, including SOAP clients
    • SQL:
      • 12+ years experience writing enterprise database applications using complex SQL queries and both Sybase and Informix stored procedure languages
    • PHP (3.x, 4.x and 5.x):
      • 10+ years experience with database driven PHP web and backend applications
      • Familiar with PEAR and PECL extensions
      • Experience with asynchronous processing using Gearman task scheduler
    • Bash shell scripting:
      • 10+ years experience using bash scripts to support applications
  • Databases:
    • Sybase Adaptive Server (11.5.x and 12.0.x):
      • 5+ years experience writing applications using Sybase database as storage
    • MySQL (4.0.x, 4.1.x and 5.x):
      • 10+ years experience of application development and administration of database server
    • Informix Universal Server:
      • 4 years experience building web applications based on IUS
  • Operating systems:
    • Microsoft Windows, Linux server and desktop, Sun Solaris server, Mac OS X
  • Version control:
    • Subversion, CVS, ClearCase
  • Bug tracking:
    • Bugzilla, Flyspray, ClearQuest
  • System monitoring:
    • Nagios, Cricket
  • Web technologies:
    • Apache Webserver, Apache Tomcat servlet engine, Spring Web Flow, Symfony, Joomla, ExtJS, Google Web Toolkit, WebObjects
  • Testing:
    • PHPUnit, JUnit, Lime
  • Other technologies:
    • Gearman, Memcache, AWS

Language and communication skills
  • Native German
  • Fluent English
  • 6+ years experience working in a multinational company with offices in the US, Germany, England, France and Ireland.