Paul Tarjan
Belmont, CA 94002

Work Experience

  1. February 2020 - October 2022
    Distinguished Software Engineer
    Robinhood - Engineering
    • Most senior engineer at the company. Worked with VP Engineering to holistically own engineering.
    • Developed, led, evangelized, and eventually handed-off weekly incident review forum.
    • Created and led group of L5+ (Staff+) engineer group from 1 (me) to 38 engineers.
    • Represented Engineering for yearly audit by Earnst & Young for SEC, FINRA and SOC audits.
    • Created Developer Productivity organization. Moved to a monorepo, added bazel, switched to continuous releases, migrated to k8s, and switched from Jenkins to Buildkite.
    • Generically filled any hole missing in Engineering (Spend analysis, continuous release, Jenkins falling over, etc.) until it was no longer a problem.
  2. January 2016 - January 2020
    Principal Software Engineer
    Stripe - Product Infrastructure, Developer Productivity, Engineering Advisors, Engineering Review
    • Founded Developer Productivity team to be responsible for Engineer velocity. Grew team from 4 of the most senior engineers to 50 across 3 offices and 2 layers of managers.
    • Coached Engineering Advisors and Engineering Review teams for company-wide senior engineering decisions.
    • Authored Stripe's Technical Architecture internal documentation about how we build our software.
    • Highest code contributor at Stripe.
    • Envisioned, staffed, and built Sorbet, a typechecker for Ruby.
  3. April 2015 - December 2015
    Founder and CTO
    • Founded startup with Amit Kumar. Congealed the product idea and worked on the execution plan.
    • Built the initial prototype, setup the entire development toolchain, infrastructure, release process, style guides, company culture, etc. Continued to be the largest code contributor.
    • Raised seed funding from prominent angels and VC firms
    • Grew the team to nine members across two offices
  4. March 2010 - April 2015
    Senior Staff Software Engineer
    Facebook - Platform, Product Infrastructure, HHVM, Web Speed
    • #14 engineer by commits. #5 by reviews. Top 40 Tech Leadership. Engineer ~#200.
    • Created and led the Web Speed team. 30% improvement in E2E in 6 months for
    • Led the HHVM Open Source team. Worked with Wikipedia, Box, and Etsy to switch compilers.
    • Wrote many Product Infrastructure abstractions:
      • Designed the DynamicYield abstraction to help migration from preparables to generator-based data fetching
      • Wrote the GenXHP UI layer which forces efficient inline data fetching instead of overfetching
      • Deleted the module system (3 million lines of code) and replaced it with an autoloader
    • Led Dublin Bootcamp
    • Founded the Open Graph Protocol 2.0 team to verb any noun on Facebook
    • Extended OAuth2 to have Signed Requests
    • Created the URL Debugger
    • Founded the College Hackathon program and MCed over 50 hackathons worldwide
    • Wrote the Registration Plugin
  5. May 2007 - March 2010
    Senior Technical Yahoo!
    Yahoo! Inc - Search
    • Founded SearchMonkey team with Amit Kumar
    • Lectured, organized, judged, and worked closely with Rasmus Lerdorf for Yahoo! HackU
    • Architected and built prototype for SearchMonkey in 2 months
    • Productionized SearchMonkey code for public release
    • Speaker and evangelist for Y! Academic Relations
    • Technical Lead for SearchMonkey team
    • Designed and implemented many features for Yahoo's site search product
  6. January 2006 - May 2007
    Research Assistant and Teaching Assistant
    Stanford University - High Performance Networking Group (Dr. Nick McKeown)


  1. 2005 - 2007
    MSc Computer Science - GPA 3.83 / 4.00
  2. 2001 - 2005
    BSc Honours Pure Math - GPA 3.91 / 4.00
  3. 2001 - 2005
    BSc Honours Computer Science - GPA 3.91 / 4.00



Publications and Patents

See Google Scholar.

Open Source

See Github.

Computer Skills

Very Knowledgeable (Buzzword Bingo):
  • ES6, Python, PHP, Hack, C, C++, Java, Ruby
  • HTML5, CSS3, DOM, JQuery, Ajax, Angular, React
  • JSON, XML, YAML, REST, OpenID, OAuth
  • Gulp, Parse, NPM, Hadoop, OpenGL, Bundler, Rake
  • Lex, Yacc, LLVM, Compiler Toolchain
  • Git, SVN, CVS, MySQL, MongoDB, SQL, UNIX/Linux
  • Perl, Lisp, Haskell, Almost everything else :)
"Pet Projects":