Fuente: WIPO "tomato" Aspects of the present disclosure relate to automated document processing systems. In particular, embodiments disclosed herein provide an architecture for seamlessly integrating code representations of electronic documents generated by various different extraction systems into a single document processing system. Certain embodiments provide for generating a code representation of an electronic document based on an entity extracted from the electronic document. The code representation includes an entity representation that comprises an index indicator appended to an identifier for the entity, which may comprise a column of items. Some embodiments provide for applying a transformation to the entity representation to produce an intermediate code representation of the electronic document, wherein the transformation comprises a format for entities or a format for entity representations. Certain embodiments provide for generating an updated code representation of the electronic document based on matching indexed item values from the electronic document to the transformed entity representation.