Systems, devices, and methods are provided for fingerprinting requests, such as transaction records. A transaction record or other suitable request may be parsed to identify a parameter values for a set of fields relevant to fingerprinting. A transaction record representation may be generated based on transaction input data, transaction output data, intermediate data, or combinations thereof. A fingerprint may be generated from the transaction record implementation. Fingerprints may be used to identify various test cases that can be used for regression testing.