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Christopher J Fox, Multithreading Developer in Can Tho, Cần Thơ, Vietnam
Christopher J Fox

Multithreading Developer in Can Tho, Cần Thơ, Vietnam

Member since January 11, 2013
Chris has over 30 years of experience in software development and architecture in a wide variety of operating systems, languages, and development environments. His specific expertise lies in servers. mobiles, software concurrency, cryptography and threat analysis, and data modeling.
Christopher is now available for hire
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Portfolio

Experience

Location

Can Tho, Cần Thơ, Vietnam

Availability

Full-time

Preferred Environment

Windows

The most amazing...

...software I've built optimized bids on federal construction projects, reducing run-time from billions of cosmic lifetimes to a half second.

Employment

  • Cryptographic Developer

    2020 - PRESENT
    Cubeitz LLC
    • Developed an intricate and tightly secure cryptographic system working on a distributed team. Learned three programming languages and worked with front- and back-end developers on tight deadlines and designed a new system with minimal specs.
    • Created an original triply-secured design using a hybrid symmetric/asymmetric system from an open set of requirements.
    • Solved numerous technical issues not explained in vague and incomplete documentation.
    Technologies: Cryptography, Tanker, JavaScript, Python, Django

  • Lead Server Developer

    2016 - 2019
    MarchingOrder
    • Maintained, debugged, and coded new features for a system assisting university graduation ceremonies.
    • Wrote documentation.
    • Analyzed performance bottlenecks.
    • Set up staging servers.
    • Wrote a bulk emailer feature.
    Technologies: C#, .NET, LINQ, Entity Framework

  • PAX Scanner Developer

    2016 - 2017
    WebTeh
    • Learned a difficult and poorly documented system.
    • Wrote a menu-driven point-of-sale system.
    • Contributed substantial progress despite nearly unusable tools.
    • Wrote HTTPS with TLS 1.3 and integrated OAuth.
    • Programmed in C.
    Technologies: PAX POS Scanners, PaxPay, Prolin

  • Sole Proprietership

    2011 - 2016
    FoxWare Can Tho
    • Learned Objective-C and iOS development in a matter of weeks (on my own initiative).
    • Wrote a cryptography library to expose the use of keychain, symmetric, and asymmetric encryption, hashing, and signing, all via simple API calls.
    • Wrote the first password generator in the App Store to synchronize multiple installations using iCloud.
    • Wrote the Photo World application using geotagged public photographs and iOS map objects to fetch and display photos chosen by location, tags, date taken, and many other parameters (rated 4.8 stars in the App Store).
    • Utilized numerous background processes and multithreading to hide network latency behind active and visible user experience.
    Technologies: iOS, Xcode, FlickrSDK, JSON

  • iOS Developer

    2015 - 2015
    Doozie, LLC (via Toptal)
    • Built a graphics- and database-intensive dual application.
    Technologies: iOS, Xcode, Firebase

  • iPhone Software Engineer

    2012 - 2012
    RADIOActive Pte. Ltd.
    • Wrote an application for a Malaysian company client to stream radio songs and advertising.
    • Developed a background download queue amenable to easy reuse with synchronous and asynchronous download options, caching, aging, and notification-based delivery.
    • Learned Facebook SDK and managed to retain compatibility all the way back to iOS 3.2.
    • Discovered undocumented recent changes to Twitter. Integrated to the new application and figured out how to get them working by sheer ingenuity (and some guesswork).
    • Developed extremely glitzy user interface tricks and animations resulting in a very engaging and original-looking application.
    • Wrote an application compatible with extremely old versions of iOS including handing in-code features not available until later versions.
    Technologies: Objective-C, Facebook SDK, Twitter SDK, JSON, Xcode, BASS Audio

  • Senior Software Engineer (Contract)

    2009 - 2010
    Real Networks, Inc.
    • Assumed responsibility for game installer at the core of the division's revenue.
    • Extended an installer based on limited scripting language with 8-bit characters to install on all Windows-supported languages.
    • Supported applications for other teams, working with a variety of languages and technologies.
    • Wrote Lua extension DLLs in C++ to make use of Windows frameworks (previously not available in Lua).
    • Wrote extensive documentation of the project with detailed explanations of operation to ease the transition of company offices.
    Technologies: Lua, C++, C#, Visual Studio

  • Senior Software Engineer DRM

    2006 - 2008
    WildTangent
    • Handled all DRM issues for a game distribution company.
    • Developed numerous content-protection schemes and improved such schemes constantly to counter hacking challenges.
    • Developed software to "inject" DLLs into games whose source code we did not have, working only with released binaries, hooking API calls and overriding them with my own code.
    • Developed a system to hide files requiring license purchase prior to use so games could not "see" them in the file system.
    • Wrote code to load and decrypt large files superior in performance to native API calls.
    • Wrote a logging layer to work directly with testers and bypass cumbersome bug-reporting/triage systems.
    Technologies: C++, Visual Studio

  • Senior Software Engineer DRM

    2002 - 2006
    Microsoft Corporation
    • Handled individualization servers underlying the entire Microsoft Media Player DRM initiative, including ownership of most protected decryption keys in use by the company.
    • Wrote a portability layer allowing DRM porting kit for portable devices to be used on MP3 players with extremely unusual CPUs, with bytes of 16 or even 24 bits (achieved 95% functionality upon the first test).
    • Designed a certificate chain for all content protection on Windows Vista.
    • Worked closely with Singaporean company to solve performance issues on a specific processor and rewrote algorithms from O(3) to O(1) after determining the problem.
    • Managed to produce an extremely slipshot check-in system (which, in the end, was so frustrating to use that some entire hallways were emptied by resignations).
    • Wrote and patented license synchronization and metering features for Windows Media Player 10 and 11.
    Technologies: Internal MS Tools, Visual Studio, Windows Media Player, C++, C

Experience

  • Photo World (Development)

    Developed an iOS application which uses the Maps API and allows viewing of public geotagged photos on social networking sites based on GPS current or selected location, photo tags, date taken, and many other parameters. Very popular with users (rated over 4.5 stars).

  • iKeyRing (Development)

    Created an iOS application for password storage with iCloud synchronization between installations.

  • NotifEye for Facebook (Development)

    Facebook monitoring application for iOS, listens for mention of search terms, topics, or hashtags either in all public content or in friends' streams. Background operation polling and "eavesdropping" on social network using Graph API. and notifications; "never miss a mention."

  • Bulk Emailer (Other amazing things)

    MarchingOrder offers services for university graduation ceremonies and includes a mass emailer service as a core feature. Native Microsoft emailer was unreliable and company staff had to identify and resend about 30% of all mailings. I wrote a completely new bulk mailer using ElasticMail and improved numerous page load inadequacies in the process. Final release was 100% reliable.

  • Why Writing Software Design Documents Matters (Publication)
    https://www.toptal.com/freelance/why-design-documents-matter
    If you're an experienced developer, you've probably progressed from being a humble tester to a senior developer, and if you're a freelancer, you've made another leap, perhaps the biggest of them all, when you started working with clients directly. Some clients aren't in the software business; they're in an entirely different industry that needs a piece of software, and they don't have a clear and precise vision of what they want from you. This is a far greater challenge than it appears, and here's what you can do to improve client communication and project documentation.

Skills

  • Languages

    C#, SQL, C, C++, T-SQL, Objective-C, FQL, Lua, Java, JavaScript

  • Frameworks

    iOS SDK, ASP.NET, ASP.NET MVC, Core Data

  • Libraries/APIs

    Entity Framework, LINQ, Facebook SDK, Twitter API

  • Tools

    Xcode, Microsoft Visual Studio, TFS

  • Platforms

    Windows, Bluetooth LE, iOS, Firebase, Android, MacOS

  • Industry Expertise

    Security

  • Storage

    SQL Server 2017, Oracle DBMS

  • Other

    Technical Writing, Documentation, Multithreading, Concurrency, Freelance Developer, IIS, Bluetooth, Cryptography

Education

  • B.Sc. degree in Mathematics
    1980 - 1984
    University of Washington - Seattle, WA

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