Josh Juran's Résumé


Josh Juran
jjuran at metamage-dot-com
GitHub:
jjuran
Twitter:
@joshuajuran

Summary

I design, build, and maintain complex software systems consisting of simple parts. I create new developer tools as needed.


Recent Projects

In between positions, I've kept my skills sharp with various projects:


Work Experience

Independent Consultant to Ted Nelson (San Francisco, CA)

June 2015 - April 2016

ZigZag is a hypergrid-based data storage and navigation system in which cells may be connected along an arbitrary number of dimensions. I built the newly canonical implementation using a curses front end. (Python)

Senior C++ Engineer at Ripple Labs (San Francisco, CA)

September 2014 - May 2015

Ripple is a payment network using a distributed ledger with some similarities to the Bitcoin blockchain. On the "rippled" team supporting the low-level server daemon, I implemented support for Ed25519 keys and signatures, as well as a protocol for propagating the deprecation and replacement of server public keys to peers (avoiding the need for all peer operators to manually edit a config file). (C++11, crypto)

Senior Software Engineer at Scale Computing (San Mateo, CA)

December 2012 - October 2013

Scale Computing's flagship product is a virtualized storage and computing cluster appliance. I designed an event-driven testbed management system with subsecond status update latency to Web browser clients, which replaced the existing poll-every-minute system; I also implemented and deployed the back end. The same architecture was then reused in a rewrite of the product's UI. (GNU/Linux, C++, pthreads, MySQL, Thrift, make)

Contractor at iSwifter (now Agawi) (Menlo Park, CA)

August 2011 - February 2012

I started off working on a multi-million-dollar support contract which involves patching Wine to enable old games to run on GNU/Linux. Additionally, I wrote a tool to automatically clean up leaked shared memory segments, which were causing server crashes. Finally I developed a proof-of-concept Windows version of a GNU/Linux server codebase, using Cygwin to port the code and Perl for rewriting Erlang code.

Employee of Adobe (Seattle, WA)

July 2007 - January 2009

Adobe's Photoshop Express is a community-oriented Web application. On the storage cluster team, I redesigned and reimplemented file uploads to avoid performance bottlenecks in lighttpd by writing a custom HTTP server optimized for receiving huge files instead of tiny GET requests. I also refactored the build scripts to avoid duplicate logic. (GNU/Linux, C++, sockets, make)

Employee of Microsoft (Redmond, WA)

March 2006 - July 2007

I worked on core aspects of Microsoft Office for Mac OS. I fixed bugs in the Compatibility Report module, ported the Test Drive (demo) timeout and tamper-detection code to the Intel architecture, and implemented changes to the Formatting Palette, including the ability to specify an alternate button shape (used for groups of buttons clustered together with the edges rounded) which was reused after the fact by another developer for a different feature.

In addition, I discovered and fixed latent bugs exposed by compiler warnings and made various improvements to the build infrastructure. (Mac OS X, C/C++, Carbon, Python)

Independent Consultant to Macquarie University (Sydney, Australia)

August 2003 - January 2005

I ported PsyScript (a scriptable application engine for administering cognitive psychology experiments) from C to C++, from Mac OS 9 to Mac OS X, and from CodeWarrior to gcc (retaining backward compatibility with CodeWarrior and Mac OS 9).

Senior Developer at LEROS Technologies (Fairfax, VA)

July - December 2002

City Sprinter is a distributed application for running a courier business written in Object Pascal for Mac OS. The included modules for communicating over several TCP-based protocols were severely broken when I began working as the sole maintainer. I eliminated crashes, data corruption, and memory leaks in general and rewrote the networking code to avoid race conditions. (CodeWarrior)

Senior Programmer/Analyst (contractor) at the National Center for Biotechnology Information

March 2001 - January 2002

I was responsible for the Mac support of NCBI's Bioinformatics C Toolkit. Most of the toolkit was platform-independent; the VIBRANT application framework was not, and I ported the VIBRANT Mac code to the Carbon API required by Mac OS X.

NCBI's Mac build system used AppleScript to create CodeWarrior project files. I refactored the build scripts to eliminate redundant code and support multiple targets.

Contractor to Buttonwood Internet (Frederick, MD)

January - June 2000

The ORBS open relay blacklisting service sent us an automated message warning that our mail server had tested positive as an open relay and would be listed as such in one week. I implemented a POP-before-SMTP solution and closed the relay before the deadline. (GNU/Linux, sendmail, Perl)

I was selected to complete the back-end of a customer Web site project after a key project member left the company. I developed Perl libraries to conduct credit card transactions through Authorize.net and the site went public on time. (GNU/Linux, Perl, CGI, HTML)

Contractor to The Learning Company (School division) (Baltimore, MD)

December 1998 - December 1999

After a manual CD-ROM imaging process resulted in repeated incorrect images, a plan was made to develop an in-house mastering utility to automate the process given a single configuration file per disc. In addition to being the sole developer on the project, I also produced the design and documentation and participated in requirements analysis. (Perl, AppleScript, DOS batch)

(Incidentally, the utility is no longer used, but the core engine (originally targeting classic Mac OS) was later deployed on Solaris by another team for a completely different project, demonstrating just how well-written the code was.)

I was asked to help eliminate a "showstopper" bug in an unrelated application, which turned out to be caused by a system software flaw. Despite there being no defect in the application code to correct, I successfully modified the code to avoid the bug. (Mac, C/C++, CodeWarrior)


Free Software Collaboration

Nitrogen

A thin but rich, type-safe, exception-safe C++ wrapper for the Carbon API of Mac OS 9 and X, Nitrogen allows design-by-contract, reduces source code size (typically) by more than half, and makes certain classes of errors impossible to make. I was the third developer to join the project and am now the maintainer. Additionally, I adapted Nitrogen's principles to develop a POSIX C++ wrapper called POSeven.

http://www.metamage.com/code/nitrogen/

Linux/m68k

Penguin is a Mac OS application which loads and executes the Linux kernel. I was the second developer to work on Penguin, and produced the first usable release.

http://www.mac.linux-m68k.org/

Obligatory XKCD

http://xkcd.com/137/