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Kalzumeus Software

I'm Patrick McKenzie. Your engineering team knows me as patio11.

The broad through line of my work is systems thinking applied to businesses. I'm best known for being at the intersection of marketing and engineering, especially in SaaS businesses. I think the social organization of the Internet and its impact on the world are underestimated by almost everyone, including Silicon Valley. My weird hobbies include credit reporting, fintech (especially discount brokerages), and cryptocurrency skepticism.

My self-assigned score is median value created for software people (engineers & entrepreneurs, principally) times number of software people impacted. Most is due to telling engineers to Charge More™ and accelerating software startups through my public work. I love talking to software people.

I am a tiny angel investor. I've lived my entire adult life in Japan.

These days I’m working at Stripe, mostly on accelerating startups. Opinions expressed on this site are my own.

Best Work

I've written extensively (2.9 million words and counting) since 2006. I curate a list of my best public work. Here's the condensed version of my personal story.

My Businesses

I spent about ten years running small software companies.

Bingo Card Creator

Bingo Card Creator makes bingo cards for teachers. This was my first business; I ran it from 2006 through 2015. Lessons learned: tiny amounts of code written for marketing outcomes move mountains. The big win was a CMS to drive SEO and AdWords.

Appointment Reminder

Appointment Reminder makes automated phone calls, emails, and text messages to the clients of professional services businesses. I founded it in 2010 and sold the business in September 2016. Lessons learned: you can engineer sales processes to directly influence SaaS math.


I was a co-founder at Starfighter with Erin Ptacek and Thomas Ptacek of Latacora. We built games that people played by programming and tried to match the best programmers with jobs. The boss level was black box security research against our fake stock exchange to deanonymize trades and then figure out how to identify an inside trader from them.

Kalzumeus Software

Kalzumeus Software was my consultancy. My typical client was a B2B SaaS company with $10 to $50 million annual revenue. My typical engagement was doing conversion optimization and lifecycle email marketing.

Recent Essays

What Working At Stripe Has Been Like

I joined Stripe to work on building financial infrastructure for the Internet. Time flies. Here is what I've learned in the first four years.

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An update on a pre-registered result about the coronavirus

A history of an anomaly in the 2020 Coronavirus Pandemic, an independent research project about it, and what we need to learn about our next steps.

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Dropping hashes: an idiom used to demonstrate provenance of documents

There exists an idiom called “dropping a hash” which is widely understood in the security community and not widely understood elsewhere. Somewhat surprisingly, there does not appear to be a canonical explanation. I have dropped hashes before and wrote this up to explain the significance of it to non-specialists.

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