Mark Hudnall

Hi, I'm Mark 👋

I'm an engineer, people manager, and founder interested in empowering technologies.

I was an engineer and manager at Coinbase, focusing on payments and backend platform. Before that, I was a founder and CTO of Clef, building a better way to log in online.

Recent posts


I like to build tools for augmentation in the sense described by Douglas Engelbart. My personal projects start from the perspective of an individual (myself), exploring questions like: How can we better organize personal knowledge? How can small groups share and collaborate with fewer barriers and intermediaries?

Beyond personal projects, my work in cryptocurrency and online identity concerns larger group dynamics, driven by questions like: How does trust manifest in groups too large to rely on personal relationships? How and why do markets fail to capture negative externalities and what can be done? What is identity and what of that do we bring online?


  • Gridliner is a 2D outliner for freeform knowledge
  • Serenity is a P2P file transfer app in the browser
  • Kiwi is a personal wiki you write in Markdown
  • plaid-cli is a CLI tool for working with the Plaid API

I maintain a handful of open source libraries that support these and other projects. I'm also interested in generative art, most recently with an HP-7550A pen plotter. See GitHub for these and other hidden gems.


  • Clef was a better way to log in online. Twilio acquired our team in 2017.
  • Instant2FA was a drop-in 2FA integration, built during the Clef days.
  • gdax_recurring is a CLI tool to automate recurring USD deposits and asset allocation for GDAX (now Coinbase Pro). It theoretically still works, but I haven't used it in years.


If you want to get in touch, you can find my email address on GitHub.