Chrome 57 and Firefox 52 shipped it a fortnight apart in March. Replacing a grid system of nested rows, negative margins and a clearfix with fourteen lines.
The email that arrived four times and the charge that arrived twice. What makes a job safe to run again, and keeping workers alive without them serving stale…
The reporting code had one caller and a six-hour test run. Finding the seam, dealing with the shared schema honestly, and routing traffic gradually rather than switching.
LIKE cannot use an index and everyone knows it. The mapping, the analyzers that decide what matching means, the indexing pipeline, and the drift it introduces.
Two days lost to PHP extension mismatches. A container per service, what the shared-folder performance problem costs on a VM, and whether it was worth it.
Five filters over 30,000 variations, and a request that never returns. Replacing EAV meta joins with a denormalised index table kept in sync by product hooks.