The collision that costs you trust
Here is the exact failure. A catalog is migrated. Certificates are matched to products by name, because name is what both systems have in common. Two products from different suppliers share a compound name — which is extremely common in this category — and both end up pointing at the same file.
Everything looks fine. The product page shows a certificate. The link resolves. The PDF opens. The only person who can detect the problem is a customer who reads the batch number and notices it does not match what arrived.
That is the worst possible discovery path, because it converts a data-modelling mistake into a credibility problem. And it is entirely avoidable by keying on the batch rather than the name.
