My name is Patrick McKenzie. I’m a recovering Japanese salaryman who ran a succession of small software companies. At present, I’m working at Stripe, working making it easier to start and scale companies worldwide.

My email address is . I’m happy to get email from you—can’t promise a reply but I do my best. See my Standing Invitation for more details.

Who are you, anyway? A great question! I write well and prolifically, generally on the intersection of marketing and engineering. I’m not the best marketer or engineer in the world, but I’m a better engineer than almost all marketers and a better marketer than almost all engineers. Tactically abusing this combination prints money in a very intellectually interesting way; this site is mostly war stories from doing that. You can read my brief bio for the highlights.

What is this Kalzumeus thing? Why the dragon logo? Kalzumeus Software is named after a dragon in a long-forgotten RPG campaign from high school. I wanted a .com for this site and it was the first thing that popped into my head which was available, and have felt insufficient desire to change, even though I really should just bite the bullet and make this

Hiya security researchers! I appreciate the work you do. If you’d like to tell me anything sensitive, drop me an email at — you’ll have my full attention.

I previously made a PGP key available. I’m deprecating it, for reasons described here. As that essay predicts, I have had mostly negative experiences with encrypted emails, including receiving 5+ private keys of security researchers.

If you need encrypted transport to talk to me, email me and ask me for my number on Signal.

Who am I?

My name is Patrick McKenzie (better known as patio11 on the Internets.)

Twitter: @patio11 HN: patio11

Bits about Money

I also write a weekly newsletter on the intersection of tech and finance.