uploading an entire camera roll to find the receipts in it is expensive, slow, and a privacy problem you then have to explain to a client.
so a mobilenetv3 classifier runs on the device and filters first. only likely receipts are sent up, which cuts the bill and means holiday photos never leave the phone.
behind it sits the unglamorous half: idempotent uploads, job claims, backoff retries, background reconciliation, and observability with the personal data scrubbed out. that is what makes it survive real users.
