When a form becomes infrastructure: maintaining an official railway concession system
Building the MPSTME Railway Concession system was only the beginning. The harder part was making it official, keeping it dependable, and staying responsible for the people and process around it.
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Building conc-qr, Social Conclave's check-in system
The system behind Social Conclave's badge scanning with role-based access, a live-editable permission matrix, and a race condition I fixed by accident while chasing latency.
The server can't read this: designing zero-knowledge sharing
How GhostShare shares notes and files in real time while making the server mathematically unable to read them — in-browser key derivation, AES-GCM, and direct-to-R2 encrypted uploads.
A B-Tree on disk: writing a storage engine from scratch
What actually happens between INSERT and the disk — building bad-db's on-disk format, a hand-rolled B-Tree index, tombstones, and compaction in plain Java.
Where LLM guardrails break: notes from running a jailbreak contest
I built a prompt-injection contest and handed a few hundred people a scoreboard and a reason to break it. Here's what actually cracks an LLM's guardrails — and what it means for defending them.