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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 writing about financial infrastructure, cryptocurrency skepticism, and running national shadow vaccination information infrastructure. (The pandemic has been weird for everyone, right?)

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

App Store Payments Will Have Increased Competition

Apple's App Store is reforming their guidelines about taking out-of-band payments. This will be very interesting for developers, especially in the games industry.

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Solving The Vaccine Data Problem

VaccinateCA, the non-profit I have been running, expanded nationally to Vaccinate The States. Here's what we've learned in the last 100 days.

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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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