Platform Engineer · Open Source Evangelist
Boring infrastructure, on purpose.
Thirty years of it, from mainframes to Kubernetes. I helped write three of the Linux Foundation's certification exams and continue to sit on the advisory council for one of them. Mail servers that stay up, zero trust that isn't theatre, and tooling I wrote because I couldn't find it.
John Coffey
Platform Engineer and Open Source Evangelist.
Latest writing
Notes from the machine room
Self-hosting, systems engineering and open source, written up after the fact by the person who had to fix it. All 143 articles, searchable.
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The Structure Stays in Your Head
Yutaka Tomii, an engineer in Osaka, says vibe coding is what he was already doing with graduate students in the 1990s. In September I wrote that AI is a tool and the judgment has…
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Your Mail Is Portable. Your Account Isn't.
Every piece of a mail account already has an open format, and you can take all of them with you. What you can't take is the account itself, meaning which folder was Sent, which…
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Open Source Theater: How to Fake a Multinational on a Hobby Budget
A step-by-step guide to making a one-person open source project look like a global company, using two mail-drop addresses, a few Internet-Drafts, the word "team" and a license…
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PHP2Shell, and Other Things Nobody Could Possibly Have Seen Coming
Two AI-found bugs in PHP's C core turned most of the web into a patch queue this week, and enterprise acted shocked again. A recap of PHP2Shell, and why the sunk cost in PHP and…
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Real Machines, No Brain Dumps: What Makes LINUXexpert Different
Most exam prep sells you remembered exam questions and labs that walk you down a single track. LINUXexpert.net runs on exam engines we built ourselves, question pools written from…
Building
Tooling I wrote because I couldn't find it
All of it open source, all of it at Coffey Labs (opens in a new tab), where the full list lives.
Spotted a mistake, or want to argue?
Corrections and questions are welcome. Bugs in the projects are best as issues on the repository, where they stay findable for the next person.