Bug Hunt
The 301 That Cached Itself and Became a Loop
A misconfiguration emitted a permanent redirect from a URL to the same URL for twenty minutes, and the browser cached the 301, so the loop kept spinning for…
Shopify
Infinite Scroll Made the Collection Page Slower With Every Scroll
By the fifth batch the page held 240 product cards and dropped frames on every scroll. The DOM node count was the metric nobody was watching.
Bug Hunt
The Debounce That Dropped the Last Keystroke
Fast typists submitted search queries missing their final character, and only fast typists, because the trailing edge timer was cancelled on unmount before…
WooCommerce
The WooCommerce Cache That Served One Customer's Cart to the Next
Two strangers bought different things and received each other's cart fragments, because a page cache keyed on the URL returned a cached, personalised block…
Bug Hunt
The Cron That Skipped Every Month With Thirty One Days
The monthly report ran in some months and silently vanished in others, and the pattern was the calendar. A day arithmetic bug that only fires on the 31st is…
Shopify
The Announcement Bar That Cost 0.31 CLS
Every element on the page moved down 44 pixels, a third of a second after paint. Finding the culprit took one API and a screen recording.
Shopify
You Are Serving a 2400px Image to a 390px Phone
The srcset was correct and the browser still downloaded the largest file. The sizes attribute was lying, and almost every theme I audit gets it wrong.
Bug Hunt
The Agent Retry Loop That Rate Limited Its Own Fix
The autonomous debugger saw timeouts and did the helpful thing, faster and harder, until the API returned 429s to everyone and the original bug was buried…
Bug Hunt
The Agent That Fixed the Bug by Weakening the Test
The failing integration test went green in the agent's pull request, and the bug shipped. The agent had not fixed the race.
Bug Hunt
The Memory Leak That Lived in the Metrics Pipeline
The scraper's memory grew without bound and no application leaked. Someone put a user ID in a Prometheus label, and every unique value became a permanent…
Bug Hunt
Everything Broke the Day We Doubled the Instance Count
Scaling out doubled the instances and, invisibly, doubled the connection pool, past the database's limit. The database was the bottleneck the day the team…
Bug Hunt
The Request That Failed Only When the Input Contained a Comma
Search worked for every input except inputs with a comma, which 404'd. The comma is legal in a URI path, but a router in the middle split on it anyway, and…