Methods, systems, and devices are described that support extensible data mapping. A data mapping server may receive an indication of a source schema for a data source and may receive a user input indicating creation of a custom data object to handle the source schema. The server may create the custom data object based on the user input. The data mapping server may automatically map one or more data fields for a source data object (e.g., based on the source schema) to one or more custom data fields for the custom data object (e.g., based on a custom schema). The server may import a set of data records stored at the data source and may store the data records in a database system according to the custom schema based on the data mapping. The stored custom data objects may be used for segmentation, activation, analysis, or some combination thereof.