1. A method of generating a user interface for validating and finalizing data received from legacy computer systems, the method comprising: receiving data records from a plurality of data sources that are associated with legacy computer systems; extracting, from the validated data records, a first set of data that is sourced by a first legacy computer system; generating a user interface that displays, together in the user interface, summary information sourced by the first legacy computer system among summary information of data sourced by legacy computer systems other than the first legacy computer system; receiving, through the user interface, a selection that selects the summary information of the legacy computer system from among the summary information of the similar data for the other legacy computer systems; causing the first set of data to be displayed through the user interface; receiving commands to edit the first set of data through the user interface; converting the first set of data into a new data format; and exporting, through the user interface, the first set of data.