Dave Aronson, Software Developer in Fairfax, VA, United States
Dave Aronson

Software Developer in Fairfax, VA, United States

Member since February 25, 2014
Dave has developed software since 1980 in a wide variety of languages, fields, techniques, and domains. He now mostly does Ruby (on and off Rails) but is also skilled in Python, C, Elixir, and much more. He is a seasoned speaker on software development topics at conferences, user groups, and podcasts. With his gathered knowledge, Dave can mentor your devs and advise on processes and tools.
Dave is now available for hire


  • Codosaurus, LLC
    GitHub, Git, Linux, OS X, NuoDB, Riak, MySQL, PostgreSQL, minitest, RSpec, C...
  • Miscellaneous
    Google Sites, HTML, C, JavaScript, Python, Ruby on Rails (RoR), Ruby
  • Rosetta Stone
    Subversion (SVN), Flash, Jazz, Trac, Linux, OS X, Ruby on Rails (RoR)...



Fairfax, VA, United States



Preferred Environment

Elixir, Ruby, Git, MacOS

The most amazing...

...thing I've developed lately is a system to translate OMG CORBA IDL to YAML, including certain specially-formatted comments.


  • T. Rex (President, CEO, Owner, etc.)

    1990 - PRESENT
    Codosaurus, LLC
    • Ran all aspects of the company, doing everything including the client work, marketing, bookkeeping, IT, and more.
    • Added features, fixed bugs, mentored junior developers, advised on tools and processes, "roadmapped" subprojects, and brought up other ideas to save time and labor, for a high-assurance guard project for the US federal government (via a prime contractor). The main code is in Ruby (with Sinatra), plus a multi-level secure in-memory IPC Linux kernel extension in C, and a testing tool originally in Python, now in Ruby. This is expected to last until late 2022.
    • Added features and fixed bugs in a Ruby on Rails retail sales floor planning system, plus a Ruby on Rails API-based query-answerer, for RBM Technologies (via Toptal). Helped define a new version of a custom query language, added new types of queries, added the ability to download results in CSV format, removed redundant data copying, removed redundant request types, converted a query answerer from a microservice to an engine, and packaged it as a gem. This resulted in bringing query time down from half an hour to, on average, just over half a second; the worst case on known common queries was about two seconds.
    • Added features and fixed bugs in the coaching section of a Ruby on Rails wellness portal for Onlife Health (via RaveTec). Introduced the use of videos for an end-of-sprint demo, reducing the chance of error during live demo. Created developer onboarding documentation on how to set up Onlife's apps and others needed in a development environment.
    • Split a service creation platform into API and UI halves for Verisign (via Celerity IT), for easier scaling. Designed the RESTful API and implemented it in Ruby on Rails. Updated Cucumber/RSpec tests and Python/Java bulk upload tools. Investigated migrating its data storage from MySQL to Riak or NuoDB. Helped out with random other projects and a friend's classes teaching Ruby.
    • Enhanced and repaired Ruby on Rails database table administration web apps for Retrieval Systems Corporation (direct client). Also advised the president and general counsel, and some dev staff, on techniques like pair programming, test-driven development, Agile project management, and other practices conducive to high software quality.
    • Added email contact retrieval to a newsletter subscription manager in Ruby on Rails for HomeActions (direct client). This included adding abilities in the Omnicontacts gem to download contact info from additional online services. Also made the upload importing happen in the background so the user could proceed with other work, fixed several bugs, refactored the code to make later addition of other email providers easier, and advised on test-driven development and other quality-enhancing development practices.
    • Adapted desktop Ruby on Rails views to mobile (mainly splitting up long forms) for Barclaycard (via Object Systems Group, as a temporary employee of theirs). Also came up with ways to ensure that the desktop and mobile views were in sync, helped BAs develop and triage use-cases.
    • Fixed bugs and added features in an event networking and session scheduling site in Ruby on Rails for Halfaker and Associates (as a temporary employee), such as profile completeness checks, day-by-day agenda view, "more like this" for sessions, detection of room booking conflicts, reports in various formats such as PDF or CSV, and having those generated in the background and emailed instead of making the user sit and wait.
    • Created a minimum viable product for a financial portfolio rebalancer in Ruby on Rails for a private individual client. This included educating the client on what a web app might be able to do in such a case.
    • Created a device-track GIS plotter demo in HTML5 and JavaScript for Department 13 (direct client). D13 had a proprietary device that would detect certain signals from certain common devices (can't say more due to NDA). They gave me a batch of data and had me create a demo of what could be done with it, including showing the movement of a given target device and associating it with other target devices. I also helped in brainstorming meetings about more applications for this data, such as creating a Palantir plug-in.
    • Created a tweet retriever in Ruby on Rails for Atomic Broadcast as part of a potential application to filter social media output.
    • Enhanced a Python group email/SMS system for Anteon (via Liqwid Networks). Added features such as sending email to individuals instead of only groups, uploading files of new users, forwarding messages, admin notifications of new users, monitoring an email address for notices to forward, reports, better workflow, and assorted security restrictions and other robustness.
    • Created a fax board initialization and diagnostic program in C for Send2Fax and configured their server to use it.
    • Created a tool to fix corrupted dBase III files, in C.
    Technologies: GitHub, Git, Linux, OS X, NuoDB, Riak, MySQL, PostgreSQL, minitest, RSpec, C, JavaScript, Python, Ruby on Rails (RoR), Ruby
  • Volunteer

    1985 - PRESENT
    • Released open-source projects, both mine and others'. Some still can be found on GitHub, and others have been lost to the sands of time, mainly dial-up BBS utilities, MS-DOS screensavers, and text file manipulation utilities.
    • Served as Speaker-Mentor, CfP-finder, and assistant CfP-list maintainer, for Toptal's Speakers Network.
    • Spoke at technical conferences worldwide, on podcasts, and at Washington-DC area or remote technical meetups, mainly on mutation testing, my "ACRUMEN" definition of software quality, and Ruby "gotchas." Details: Spoke at JSConf Hawai'i 2020, RubyConf 2019, Little Rock Tech Fest 2019, Heartland Developer Conference 2019, Abstractions 2019, American Mensa Annual Gathering 2019, Software In Practice/Software Practice Advancement 2019, NDC Oslo 2019, Nova Codecamp 2019, CodeCamp Chisinau 2019, DevConf Poland 2018, several Metro Washington Mensa Regional Gatherings, Elixir Remote Meetup, Tech Talk DC Meetup, Joy of Programming DC Meetup, DC Ruby Users Group, NoVa Ruby Users Group, and Arlington Ruby Meetup, and on Try-Catch, Ruby on Rails, and Ruby Rogues podcasts. Scheduled to speak at DevTalks Bucharest 2020, and WeAreDevelopers World Conference 2021. (Also chosen as backup speaker at RubyNation 2018, but no slots opened. Chosen to speak at ITAKE 2019 and WeRockIT 2020, but those have been postponed indefinitely, and Codestock 2020 and Voxxed Days Athens 2020, but those were canceled.).
    • Founded and ran the LinkedIn “Plain Old C Programming” group. Managed LinkedIn “Rubyists” and “Ruby on Rails” groups. Co-managed the Facebook "Ruby Programming" group.
    • Managed Google Plus "Ruby Programming Language community" until Google Plus went away.
    • Served as organizer (president) of the "DC Computer Consultants" (remnants of ICCA of Greater Washington), and "Independent Consultants of NoVa, DC, & MD" Meetup groups.
    • Served as an electronic participant for IETF (Internet Engineering Task Force); credited for input in RFC 3458.
    • Served as webmaster for Metropolitan Washington Mensa and Fairfax Toastmasters. Also served in all other Toastmasters' local club officer positions, plus Area Governor. Served as webmaster of District 29 Toastmasters, and Mount Holyoke Club of Philadelphia.
    • Created and organized Ruby DAY Camp 2013, an overflow event for Ruby DCamp.
    • Contributed to “C Secure Coding Standards” book and website for CMU SEI CERT.
    Technologies: Google Sites, HTML, C, JavaScript, Python, Ruby on Rails (RoR), Ruby
  • Developer IV

    2010 - 2011
    Rosetta Stone
    • Created and enhanced games and related tools such as content-set editors.
    • Added those games and tools to Ruby on Rails pages, passing data via JavaScript.
    • Added new pages to a Ruby on Rails site engine, modifying the controller and views.
    • Mentored junior staff by reviewing code and conducting software engineering training.
    • Proposed ideas for new games.
    • Integrated with components from other teams or third parties (such as web analytics).
    Technologies: Subversion (SVN), Flash, Jazz, Trac, Linux, OS X, Ruby on Rails (RoR), JavaScript, ActionScript
  • Senior Software Engineer

    2009 - 2010
    Comcast Cable
    • Wrote Ruby, Python, and Perl programs to record device performance data.
    • Created a Ruby on Rails web application to record and estimate the risks of projects, broken out by various types of risk.
    • Created a data file clearinghouse to streamline the data-file transfer agreement process, in bash script.
    • Assisted in the security design and implementation for a single-sign-on effort.
    • Elicited requirements from other teams to determine needs for performance recorders.
    Technologies: Subversion (SVN), Jira, Kerberos, Linux, OS X, Shell Scripting, Perl, Python, Ruby
  • Senior Lead Software Engineer

    2004 - 2009
    BAE Systems
    • Created multiple frameworks for rapid development of near-real-time data guards (traffic scrubbers) since our extant frameworks were too slow. Used those frameworks to create data guards for demos and for clients, including NRL (Naval Research Laboratory), NATO C3A (North Atlantic Treaty Organization's Command, Control, and Communications Agency), NTT Data, and other parts of BAE Systems.
    • Developed a week-long training class on information security principles; how to install, use, program for, and administer STOP OS; how to use my main framework, and our main older one; and other BAE Systems products. Taught this class to NATO C3A (in The Hague), NTT Data (in Tokyo), Lockheed-Martin (in Ft. Worth, Texas), and assorted BAE Systems personnel (both the American company BAE Systems Inc., and its British parent BAE Systems plc).
    • Architected the next generation of the DSG data guard system and wrote its internal message transport system. Helped analyze security flaws in the previous generation.
    • Modified the STOP 6 OS networking stack to let it read and write raw Ethernet packets, to let it act as a DHCP server or client.
    • Helped adapt Samba for use as an MLS (multi-level secure) file server for use on F-35 JSF (joint strike fighter) mission plans. Traveled to Ft. Worth to install STOP and our Samba at the Lockheed-Martin plant producing F-35s.
    • Co-developed weekly CISSP (Certified Information Systems Security Professional) certification exam preparation classes for colleagues, and co-taught it for a full run of twelve weeks.
    • Taught seminars on modern software engineering techniques such as pair-programming and TDD (test-driven development).
    • Enhanced and maintained the STOP 7 operating system installer and a package installer/upgrader.
    • Tested the functionality of most of our compatibility-patched versions of BusyBox and other open-source utilities, under STOP 6 and 7, and submitted the patches upstream.
    • Founded a Toastmasters club (first new club in District that year) and served as president and webmaster.
    • Won the Chairman’s Award for Innovation (for “helping F-35 get off the ground”); was nominated many other times for the Chairman’s Award for Innovation or for Transferring Best Practices.
    • Won a Certificate of Achievement for Outstanding Service and Performance.
    • Won a spot award for rescuing the company's reputation with a disgruntled client, which resulted in multiple man-years of additional business. Traveled to Charleston, SC to pair-TDD with their team lead many times.
    Technologies: Subversion (SVN), CVS, Windows, Linux, Shell Scripting, Java, C
  • Senior Software Engineer

    2003 - 2004
    Secure Software
    • Fixed and enhanced a static analyzer that inspected many different languages, in C.
    • Fixed and enhanced a static analyzer that inspected binaries, not human-readable source code.
    • Wrote Python static analysis plugins to find usage of mobile code or files in Java, and usage of the Windows registry in C or C++.
    • Made memory leak hunting easier by enhancing the memory allocation library.
    • Helped plan test procedures as part of a code quality initiative.
    Technologies: Assembler, Subversion (SVN), Windows, Linux, FreeBSD, OS X, Java, C++, C, Python
  • Senior Software Engineer

    2001 - 2001
    Cryptek Secure Communications
    • Wrote a monitoring program in C++ for Windows to detect frozen VPN devices (external versions of our network cards), save sniffer logs, and either power-cycle the frozen device or failover to backup device.
    • Wrote requirements, use cases, and visual prototypes for a new management console for an IPsec (Internet Protocol Security)-based VPN (Virtual Private Network) using our network cards.
    • Researched management GUIs of top ten IPsec-based VPNs and presented a competitive analysis to my supervisor and colleagues.
    • Improved throughput by writing a utility to set the Ethernet MTU (Maximum Transmission Unit) on any version of Windows.
    • Wrote a manual test plan for the current VPN management GUI.
    Technologies: Visual SourceSafe, Linux, Windows, C++
  • Senior Software Engineer

    1999 - 2001
    • Added VPIM (Voice Profile for Internet Mail) 3 to a Unified Messaging platform. Discussions in IETF Working Group creating the standard led to credit in RFC 3458.
    • Enhanced and maintained a system for mobile non-SMS notification of office voicemail, using the normal mobile-account message-waiting indicator instead.
    • Co-wrote a multi-process multi-threaded tool simulating 1,400 users per PC.
    • Invented a way to change sound file speed, preserving quality better than simple interpolation while retaining greater speed than Fast Fourier Transforms; partially prepared the patent application, including a library containing the function.
    • Added a Zmodem file transfer protocol to a telnet/dialup VT100 emulator.
    • Added more languages to a text-to-speech server.
    • Created SCE (Service Creation Environment) scripts to allow the UM platform to act as a client for an advertising server to support free cell phone service.
    Technologies: Lotus Notes, Telephony, Unified Communications, Unix, C++, C
  • Software Engineer

    1997 - 1999
    Template Software (now part of Cicero)
    • Created an ORM for an EAI subsystem.
    • Helped design a new GIS data format.
    • Updated GIS format-translation and filtering functions and utilities to use the new format.
    Technologies: Rich Communication Services (RCS), AIX, Linux, GIS, Enterprise Application Integration (EAI), Libraries, Object-relational Mapping (ORM), C
  • Software Engineer

    1995 - 1996
    Telemet America
    • Added new data items to be transmitted.
    • Added new calculations to the display.
    • Created a new sales contact tracking system.
    • Ported data from the old sales contact system to my new one.
    Technologies: Visual SourceSafe, Microsoft SQL Server, Visual Basic, Mac OS, Windows, C++, C
  • Branch Chief of Systems Engineering

    1992 - 1995
    R&K Engineering
    • Wrote and ran periodic and ad-hoc SQL queries on an Army real-property Oracle database, including figuring out how to extract the desired combinations of data.
    • Developed a flexible SQL query constructor and result display, as part of a facility planning, tracking, and analysis system for the IRS (Internal Revenue Service).
    • Documented and enhanced BRAC (Base Realignment And Closure) calculations in a COBRA (Cost Of Base Realignment Actions) program for the DoD (Department of Defense).
    • Enhanced other real-property database management programs.
    • Investigated potential new technology, fixed technical problems, provided general IT support, etc.
    • Supervised and coached a programmer/technical support person.
    Technologies: Content Management Systems (CMS), Windows, MS-DOS, REXX, Fortran, Object Pascal, Oracle, Unix, Pro*C, C, SQL
  • Consultant

    1989 - 1990
    COMTEK Services
    • Created the user interface for MCI’s phone network monitoring and configuration system.
    • Tested an alarm propagation subsystem for the network element configuration system.
    Technologies: VOS, VMS, C
  • Senior Software Engineer

    1987 - 1989
    Mead Data Central (now Lexis-Nexis)
    • Continued work on communications protocol implementation, from BDM days.
    • Fixed and enhanced database software for newspaper/magazine article lookup by countries and topics (out of a preset list).
    • Replaced creation of SQL to find the articles in Oracle, with "indexed files" (a capability of Stratus VOS), reducing typical search time from several seconds to under one.
    • Created software to serve up newswire articles using freeform boolean text searches, including reception over a proprietary protocol, indexing, storage, reception of the query, interpretation of the query, finding results, and serving up results to client.
    Technologies: SQL, Oracle, VOS, C
  • Assistant Programmer and Analyst

    1985 - 1987
    BDM (Braddock, Dunn, & McDonald; now part of Northrop-Grumman)
    • Wrote a system health monitor for the company VAX center.
    • Wrote an idle process killer for the company VAX center.
    • Researched same-user same-account inter-project security and accounting for the company VAX center.
    • Wrote parts of a war game system for Air Force University.
    • Wrote a weapons accuracy plotter for the JTSC (Joint Test Support Center).
    • Wrote a generic-printer histogram plotter for the JTSC.
    • Wrote a troop unit strength calculator and comparator for the CIA (Central Intelligence Agency).
    • Enhanced a program to analyze or design (derive behavior from measurements, or vice-versa) various types of physical shock isolators for the United States Air Force.
    • Co-wrote multi-process multi-threaded communications software to handle transactions sent over an X.25-like proprietary protocol for LexisNexis (who then hired me).
    Technologies: GRID, PCL, CDC, VOS, SAP VMS, Fortran, MS-DOS, Pascal, Clipper, dBASE, C


  • Mutation Testing talk (Other amazing things)

    My talk on Mutation Testing, from RubyConf 2019.

  • ACRUMEN talk (Other amazing things)

    My presentation on ACRUMEN, my new simple definition of software quality, from Little Rock Tech Fest 2019. Sorry for the horrible A/V quality, it's just from my old phone on a tripod, as this conference does not record the talks.

  • Open Pantry (Development)

    Simplify overly complex code, add tests, and shut up a bunch of warnings (by making the code right, not just telling the compiler to shut up), for an open-source project to feed the hungry, in Elixir with the Phoenix web-application framework.

  • Rubocop Improvements (Development)

    Pull requests to Rubocop, including making it allow certain styles it previously did not realize, but that I prefer, such as allowing braces on procedural one-line blocks but otherwise following "semantic" block delimiting.

  • Pull Request Roulette (Development)

    A site to match up open source projects on GitHub that have pull requests that need to be reviewed with people willing to do the review. Not all that much there now, but please see the README and the issues at the GitHub repo (https://github.com/davearonson/pull-request-roulette/) for what I have in mind for the long term.

  • Hook Lying Syncer (Development)

    A Ruby gem to keep method_missing and respond_to_missing? in sync to make metaprogramming easier and more reliable.

  • Assorted Open Source (Development)

    Assorted things I've released as open source; some are already included in this list individually.

  • Ruby Gotchas (Other amazing things)

    Slides from my Ruby Gotchas presentation.

  • Ruby on Rails Best Practices and Tips by Toptal Developers (Publication)
    This resource contains a collection of Ruby on Rails best practices and Ruby on Rails tips provided by our Toptal network members.


  • Languages

    Ruby, C, JavaScript, HTML, SQL, Assembler, Elixir, Python
  • Other

    Software Engineering, Presentations, Leadership, Public Speaking, Software Design, APIs, Ruby Gems, API Design, Client-server Model, Technical Training, Software Consulting, GitFlow, HTTP, SaaS, Application Security, Web App Development, Shell Scripting, Kerberos, Unified Communications, Telephony, Communication
  • Frameworks

    Ruby on Rails (RoR), Phoenix, Sinatra
  • Libraries/APIs

    Rails Engines, REST APIs, jQuery
  • Tools

    GitHub, Git, Mercurial, RSpec, GIS, Cucumber, Rake
  • Paradigms

    Scrum, Agile, Agile Software Development, Test-driven Development (TDD), Behavior-driven Development (BDD), Unit Testing, Object-oriented Programming (OOP), Object-relational Mapping (ORM), Functional Programming
  • Platforms

    MacOS, Linux, Unix, Heroku, Mac OS
  • Storage

    JSON, PostgreSQL, MySQL, NoSQL


  • Bachelor's degree in Computer Science
    1984 - 1985
    Arcadia University - Pennsylvania


  • Advanced Communicator and Leader, Bronze (ACB/ALB)
    Toastmasters International

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