Mobile throwing away the document type on upload
The mobile dynamic form renderer hardcoded the document type on upload, discarding a taxonomy that already existed end to end in the backend.
Built, and nothing used it
Shipped, typechecked, dependency-injected, unreachable. Nothing ever called it.
Building the Documents Center, the plan was a document-type filter. The taxonomy already existed end to end — program_document_requirements seeded into document_requests on application creation, with a working attach endpoint already open to customers. Mobile just never used it: its only upload path, the generic file field in the dynamic form renderer, hardcoded document_type = 'attachment' for every file a customer ever uploaded.
So the schema had been right for months, the endpoint had been right for months, and the product was discarding the information at the last step — which meant every document in the system was typeless and the filter I was about to build would have had one value in it.
When a feature "needs new data," check whether the model already has it and the client is dropping it. Cheaper to fix and much easier to miss than a real gap.