7. A non-transitory computer-readable medium comprising stored computer program instructions that when executed cause one or more processors to: store a plurality of application indexes, wherein each application index corresponds to one or more application categories of a plurality of application categories, wherein each application index comprises identifiers for a plurality of application representations, and wherein a subset of the application indexes are associated with a partner system; receive a search query from a computing device associated with the partner system; identify an application category based on the received search query, the application category indicating a platform executing on the computing device; select an index from the plurality of application indexes based on the identified application category and a partner identifier of the partner system; query the selected index corresponding to the identified application category to identify a first plurality of application representations associated with the identified application category; identify a second application category based on the received search query; select a second index from the plurality of application indexes based on the second identified application category and the partner identifier; query the second index to identify a second plurality of application representations corresponding to the second application category; generate search results based on a union of the first plurality of application representations and the second plurality of application representations; and provide, for display, the generated search results to the computing device.
7. A non-transitory computer-readable medium comprising stored computer program instructions that when executed cause one or more processors to: store a plurality of application indexes, wherein each application index corresponds to one or more application categories of a plurality of application categories, wherein each application index comprises identifiers for a plurality of application representations, and wherein a subset of the application indexes are associated with a partner system; receive a search query from a computing device associated with the partner system; identify an application category based on the received search query, the application category indicating a platform executing on the computing device; select an index from the plurality of application indexes based on the identified application category and a partner identifier of the partner system; query the selected index corresponding to the identified application category to identify a first plurality of application representations associated with the identified application category; identify a second application category based on the received search query; select a second index from the plurality of application indexes based on the second identified application category and the partner identifier; query the second index to identify a second plurality of application representations corresponding to the second application category; generate search results based on a union of the first plurality of application representations and the second plurality of application representations; and provide, for display, the generated search results to the computing device. 11. The non-transitory computer-readable medium of claim 7 , the instructions further comprising instructions to cause the one or more processors to: prompt an end user to select the second application category based on one or more query terms in the received search query.