A product search, a filter list that kept growing, and a status code I hadn't seen in years. Filters went in the query string, the way they always do. That held up fine until someone saved a "filter set" with a few hundred SKUs in it and the endpoint started answering with 414. I rebuilt a small version of it to find the exact wall. Same search, filters as repeated ?sku= values, count going up in steps of a hundred: 1) GET with filters in the URL 100 filters | request line ...