1. A system comprising: a point of sale (POS) device associated with a merchant, the POS device comprising: a port; a payment reader configured to read payment instruments and detachably couple to the port; a display; one or more processors; and one or more computer-readable media storing instructions executable by the one or more processors, wherein the instructions program the one or more processors to: receive, while the POS device operates in an offline mode, a request to process a payment instrument to satisfy a cost of a transaction; determine that the POS device is operating in the offline mode; store, at the POS device and based at least in part on determining that the POS device is operating in the offline mode, information regarding the payment instrument and an indication of the cost of the transaction; determine an amount of time to indicate on the display that the payment instrument is being processed, the amount of time based at least in part on a time taken to process a previous transaction with a previous payment instrument that occurred while the POS device or another POS device was operating in an online mode; display, for at least the amount of time, an indication that the payment instrument is being processed, the indication representing an artificial processing delay; transition, based at least in part on determining that the POS device has established network connectivity, from the offline mode to the online mode; and send, based at least in part on transitioning from the offline mode to the online mode, the information regarding the payment instrument and the indication of the cost of the transaction to a remote service; and a remote system configured to receive the information regarding the payment instrument and the indication of the cost of the transaction.