Performance
The Stylesheet That Blocked the Render for Two Seconds
One render-blocking sheet on a third-party font service held the first paint, and the page had no content to show while the browser waited on CSS it barely…
Latest
DevOps
The latest Tag That Deployed Yesterday's Build
The image tag never changed, so the node used its cached layer and the new code never ran, and the deploy reported the new version while the container…
Code Review
Reviewing the Async Call Nobody Could Cancel
The request had no timeout and no cancellation, so the abandoned navigation left the fetch running, and the response wrote to a component that no longer…
Opinion
A Feature Flag Is a Debt You Take On Deliberately
The flag buys a safe release and costs a branch nobody removes, and the cost compounds because the code keeps both paths alive forever, and the forever is…
Deep Dive
What a Connection Pool Is For, and the Setting That Ruins It
The pool was raised to two hundred to fix the timeouts, and the database got slower, because the connections were the contention rather than the cure, and…
Bug Hunt
The List That Changed Because Two Variables Held the Same Array
The helper sorted the array in place and returned it, so the caller's original was reordered too, and the second consumer saw a list nobody had touched, and…
Error Autopsy
The Presigned URL That Expired Mid-Upload
The upload took longer than the signature window, so the final chunk was rejected with a 403, and the client reported a network error rather than an expiry…
Ecommerce
The SKU That Pointed at the Wrong Variant After the Import
The bulk import matched on the title rather than the identifier, so the sizes were shuffled, and the warehouse picked the wrong item until the returns…
Security
The Session Token in localStorage That Outlived the XSS
The token was readable by any script on the origin, so the injection took it and used it from elsewhere, and clearing the cookie would not have mattered…
Performance
The Loop That Read and Wrote the DOM a Thousand Times
Each iteration measured an element and then changed a style, so every read invalidated the layout and forced a synchronous reflow, and the frame budget went…
DevOps
The Cron Job That Overlapped Itself and Doubled the Work
The nightly export ran longer than its interval one evening, so two instances ran at once and both wrote to the same output file, and the file was half of…
Tooling
The tcpdump Capture That Showed Who Sent the Reset
The connection dropped at the same byte count every time, and the capture showed the reset arriving from the load balancer rather than from the application…