An information processing system according to an embodiment includes a conversion proxy that is connected to devices corresponding to a plurality of types of unique standards, and further connected to a common platform server that performs data exchange with applications. The conversion proxy includes an acquisition unit that acquires ontology data described with a data structure corresponding to the unique standards, a device management unit that acquires and manages device information that is unique to devices corresponding to the unique standards, and a common exchange unit that creates a resource in which a data structure common to the plurality of types of unique standards and a data exchange interface corresponding to the unique standards are correlated, on the basis of the ontology data and the device information, and performs data exchange with the common platform server using the resource.