Blog
Debugging write-ups, performance work, and migration notes. Filter by topic, or read straight down from the most recent.
10 posts
Sorted by newest first
A Worker that served GET requests without complaint started rejecting every POST from the browser with an opaque CORS error. The request never reached my handler at all, because the preflight was answered long before my routing logic ran.
Read moreabout Cloudflare Workers Reject POST Requests with a CORS Preflight Failure
Generating field identifiers with a random UUID looked harmless until React started warning about mismatched markup on every page load. The server and the browser were each producing a perfectly valid id, just never the same one.
Read moreabout Next.js Hydration Mismatch: Random UUIDs Render Different HTML on Server and Client
Two background jobs writing at the same time turned a reliable SQLite database into a source of intermittent failures. The database was behaving exactly as documented, and my connection setup was quietly asking for trouble.
Read moreabout SQLite Returns SQLITE_BUSY During Concurrent Writes in Drizzle ORM
The desktop build worked on my machine and on every teammate machine, then failed on the build server with a module that supposedly could not be found. It was there the whole time, compiled for the wrong runtime.
Read moreabout Electron Builds Pass Locally but Fail on CI With a Missing Native Module
An export job wrote thirty thousand rows to a file and produced a file with about nineteen thousand in it. Nothing threw, nothing logged, and the process exited successfully every single time.
Read moreabout Node.js Streams Silently Drop Data When You Forget Backpressure
A dashboard query went from forty milliseconds to nine seconds after one product decision: show the newest results first. The pipeline was fine. The sort had nowhere to run except memory.
Read moreabout MongoDB Aggregations Get Slow the Moment You Sort on an Unindexed Field