jcrenshaw.dev
john
About

I built other people's software for a living. Now I build my own.

The work was real, the systems shipped, and almost none of it was ever mine to keep.

Early on, at a shop called EAS Technologies, I wrote retinal biometric access-control devices in C++, back when biometrics was something you read about in spy novels instead of something you walked past on the way into a building. Hundreds and hundreds of them went into the field. Around the same time I wrote the software that programmed Intel EPROMs against silicon that hadn't shipped yet. After that came the tour. A last-minute Y2K contract converting a stock-and-commodities trading system off an IBM System/36, COBOL to C#, on a deadline that physically could not move. WorkBroker at The Rawlings Company, a distributed compute grid that ran on idle office PCs after everyone went home, mining Medicare and Medicaid subrogation cases by the thousands a day, all of it under HIPAA. Then a decade at Salesforce on a multi-threaded C# service that spoke SMPP to the carriers, moving SMS for Marketing Cloud at platform scale and eventually lifting it onto Hyperforce. You can blame me for some of those texts.

I was good at it. That was never the problem. The problem was spending four decades knowing exactly what I'd have done differently and having it not be my call, because the platform was someone else's, the deadline was someone else's, and whatever I built belonged to someone else the moment it shipped.

I retired in March 2024 figuring I was done with code. The break held about a year, until a weather applet that wanted me to enter my latitude and longitude by hand dragged me back in. This isn't 1981. My husband Ben, who's had thirteen years of marriage to get tired of me griping about bad software, told me to learn Rust and do better. So I did. The first thing I built was Tempest, a weather applet for COSMIC that doesn't make you type in coordinates. Powercurve followed, a power-management daemon with real fan curves for the Linux desktop. I started inside COSMIC and the work has spread out across Linux from there.

The blog is where I work through the rest. Linux as a daily driver, why open source still matters, the surveillance machinery quietly getting wired into ordinary software, and whatever else won't leave me alone. Some of it is technical. Some of it is just me arguing with an industry I spent my whole career inside. The code lives on GitLab.

I was there for the BBS era, the DOS days, the OS/2 detour, the Windows decades, the Apple years, the AWS sprawl, and now Linux. On my own machine, running Arch, in Chicago with Ben, finally building things that are mine.

selected systems

retinal biometric access control
eas technologies
intel eprom tooling, pre-release
eas technologies
cobol trading system → c#
wall street · y2k
workbroker idle-pc compute grid
the rawlings co.
smpp / sms at platform scale
salesforce