Darsey Litzenberger
(Formerly: Dwayne Litzenberger)
Software Engineer


Employment Experience

Aug 2014 - Nov 2014 Software Engineer
InboxApp, Inc., San Francisco, CA, USA
  • Information Security
  • Develop credential storage & proxy server to prevent compromise of plaintext passwords in authenticated IMAP & SMTP connections.
  • Identify security issues and risks, and develop mitigation plans
  • Technology: Python 3, Flask, Docker, Ansible, NaCl/libsodium, protobufs, capability-based access control.
Jul 2012 - Aug 2014 Software Engineer
Dropbox, Inc., San Francisco, CA, USA
  • Design, implement, and deploy performance, usability, and privacy improvements to the Dropbox desktop application software.
  • Development of best practices for managing the complexity and engineering cost of maintaining a large code base.
  • Security reviews of software, processes, protocols, use of cryptography, etc.
  • Cross-platform Python software development.
  • Experience working with large-scale distributed systems.
  • Technology: Python, Pylons, C, Objective C, Go.
Nov 2008 - Jun 2012 Software Developer, Research and Development
PatientWay (Infonium Inc.), Ottawa, ON, Canada
  • Patient self-service technology for hospitals and other health-care organizations.
  • Designed, developed, and maintained several key pieces of PatientWay's products, based on the needs of patients and hospital staff, internal objectives, and technical constraints
  • Designed and implemented back-end integration technology—using a variety of HL7 messaging, scriptable terminal emulation, Windows GUI scripting, and SQL access—depending on customer needs and the existing, site-specific configuration.
  • Developed a scriptable terminal emulator from scratch, with customer usability, fail-safety, and auditability in mind. An old version is available on GitHub.
  • Developed flowchart-based workflow engine and language, designed to enable multiple people with varying levels of technical and domain expertise to create and modify the same program.
  • Received training and familiarity with agile software development methodology.
  • Technology: Ruby on Rails, running on Glassfish/J2EE using JRuby.
May 2007 - Apr 2008 Information Technology Analyst
Open Systems Canada Limited, Regina, SK, Canada
  • Provided IT consulting to OSCL's customers; Developed internal systems.
  • Developed a robust rsync-like customer data backup system.
  • Recovered customer data manually after hardware RAID failure.
  • Isolated a deadlocking bug in Paramiko (a Python SSH implementation).
  • Discovered cryptographic weakness in random number generator in Paramiko.
Jan 2006 - Apr 2008 Self Employed
Ice Pillar Computing, Regina, SK, Canada
  • Developed software and provided advice to serve the needs of my customers.
  • Installed and maintained LAMP servers. Performed Drupal 5->7 migration.
  • Wrote screen-scraping software in PHP for a mobile application platform. (Bluepulse)
  • Developed an assortment of free/open-source libraries in PHP.
  • Wrote software to process SHOUTcast streams and MP3 files.
May 2005 - Aug 2005 Embedded Systems Software Developer, Operating Systems Group
Research In Motion, Waterloo, ON, Canada
  • Developed and maintained BlackBerry operating systems.
  • Ported the BlackBerry bootloader/firmware loader to new hardware.
  • Wrote and analyzed security-sensitive code in BlackBerry operating systems.
  • Implemented an entropy-gathering cryptographic random number generator.
  • Most work was done in C and ARM Thumb assembly language.
Sep 2004 - Dec 2004 Protocol Tester, Systems and Interoperability,
Research In Motion, Waterloo, ON, Canada
  • Performed protocol testing and wrote test automation software for GSM/GPRS BlackBerry handhelds.
  • Refactored a portion of the control software for automated testing of BlackBerry handhelds.
  • Assisted in the design of a more comprehensive automated testing framework for BlackBerry handhelds.
Jan 2004 - Apr 2004 Engineering Assistant, Research & Development,
SaskTel, Regina, SK, Canada
  • Worked with TRLabs on several research projects.
  • Improved an existing ultrasonic position-tracking system.
  • Designed a (different) ultrasonic position-tracking system with a focus on increasing flexibility and lowering per-unit costs.
  • Constructed a working prototype of a low-cost ultrasonic sensor device.
Sep 2001 - Apr 2003 Systems Analyst, Operations,
LFC Hosting, Regina, SK, Canada
  • Performed various programming, troubleshooting, system administration, and customer support duties.
  • Analyzed, designed, proposed, and implemented software automation changes to address internal and customer needs.
  • Provided technical leadership in software and infrastructure development.
  • Developed hardware keyboard access control system using iButton key fobs.
Summer 2001 Network Security Administrator, Operations,
LFC Hosting, Regina, SK, Canada
  • Designed new LAN with Linux firewall for improved resilience against attack.
  • Worked with customers and employees to resolve various technical issues.


September 2001 - May 2006
Bachelor of Applied Science, Electronic Systems Engineering
University of Regina, SK, Canada
Co-operative Education Program; With Distinction
GPA: 84%

Skills & Non-Employment Experience

Contributions to Free and Open-Source Software (FOSS)

Electronics Engineering / Embedded Systems

Computers / Information Technology


Especially interested in high-impact work that is aligned with the public interest. Examples include (but not limited to):