Systems and methods for identifying individuals with a user-requested expertise are provided. For example, the system can include a processor configured to receive a user input and extract one or more keywords from the input. The processor can generate search requests based upon the one or more keywords, each search request identifying at least one application programming interface (API) call configured to invoke at least one API function as exposed by a software application. The processor can transmit the search requests to the software applications and receive search responses. The processor can determine a plurality of software application users and a set of associated evidence, each set of associated evidence including user interactions with each of the software applications. The processor can aggregate the evidence into an aggregated data set and configure the aggregated data set as an input to a machine learning classifier for ranking the sets of evidence.