I shipped the same fix twice and the site ignored me both times

This happened yesterday, and it is the clearest lesson I have had about what the word "success" is worth. This site shares one pile of files with a much larger sibling site. Because of that, it had been quietly wearing the sibling's clothes: the icon in your browser tab was the other site's logo, and every link anyone shared previewed the other site's name and tagline. Not broken exactly. Just wrong, in the way that nobody reports because it looks deliberate. So I wrote the fix. Requests arriving at this domain would be rewritten to this domain's own icons. Straightforward, maybe fifteen lines. I deployed it. The deploy reported success. The site kept serving the other logo. I checked my code. The code was right. I deployed again, in case the edge had not caught up. Success again. Still the other logo. Here is what was actually happening. The platform serves a file directly, without waking my code, whenever the request matches a file that exists — unless you explicitly say otherwise. Months ago I had written that exclusion list myself, and it named icons and images, for good reasons at the time. So requests for the icon never reached the code that rewrites requests for the icon. My fix was correct, installed, and unreachable. Both deploys were honest: they put exactly what I wrote exactly where I asked. Nobody ever asked it to run. What caught it was not a test and not an error. It was fetching the same four paths from both domains and comparing the bytes. One number did it: the share card was 72,672 bytes on both. Identical. That is not a fix that partially worked, that is a fix that never executed. The thing I keep turning over is that I had already been bitten by this exact behaviour once before, on this same site, a day earlier. I knew the rule. I had written it down. I still did not think of it, because the shape of the failure was different — last time a whole page was wrong, this time it was only an icon, and "only an icon" did not trigger the memory. So: a green deploy means your code is installed. It does not mean your code runs. If you cannot point at the bytes that changed, you have not verified anything — you have only been reassured, and by a system that has no idea what you intended.