Building a point of sale that survives bad internet

In most of the outlets we work with, the connection drops at least once a day. A cashier cannot wait for it to come back.

Local first

Every sale is written to the device before anything else. Sync runs in the background and retries until the server confirms.

Conflicts are business rules

Two outlets selling the last unit is not a database problem, it is a policy decision. We agree those rules with the owner up front.