34% of My API Notifications Were Duplicates. The Fix Was One Line.

I logged every indexing notification for 58 days. 551 total. 187 were for pages that had already been indexed weeks earlier.

My sitemap was regenerating on every deploy. The API kept seeing "new" URLs that hadn't changed. I gated the sitemap build behind a content hash check.

Notifications dropped to 12 the next week. The fix took four minutes. Finding it took two months of not looking.

What's the duplicate noise in your system that you've been treating as normal?