1. A computer-implemented method, comprising: receiving an electronic request to determine a user identity, the electronic request including a set of values for a corresponding set of fields; transforming the set of values into a set of search terms; computing a set of inverse document frequencies for the set of search terms based at least in part on a number of records in a data set of historical records; determining a set of matching historical records matching at least one term of the set of search terms; for each historical record of the set of matching historical records: computing a set of search term results, each search term result of the set of search term results at least indicating whether: a search term corresponding to the search term result: matches a corresponding field value in the set of matching historical records, corresponds to an empty value in the set of values, or is a mismatch to the corresponding field value; and filtering, based at least in part on the set of inverse document frequencies and the set of search term results, the set of matching historical records to obtain a subset of the set of matching historical records; passing inverse document frequencies of the subset of the set of matching historical records through a random forest to obtain a set of confidence scores, each confidence score of the set of confidence scores corresponding to a historical record of the subset of the set of matching historical records; determining, based at least in part on the set of confidence scores, a determined user identity associated with a historical record from the subset of the set of matching historical records; and providing the determined user identity in response to the electronic request.