Determining a document type of a digital document

A computer-readable non-transitory storage medium comprising executable instructions that, when executed by a computer system, cause the computer system to:

• execute a first machine learning algorithm (MLA) classifier in order to determine a document type for a digital document, wherein the first MLA classifier is associated with a first hierarchical order of execution, and wherein the first MLA classifier is trained on a first trained dataset containing a first document type and a second document type, wherein the first document type is confidently predictable by the first MLA classifier and the second document type is not confidently predictable by the first MLA classifier;
• and
• responsive to determining that the first MLA classifier produced the second document type for the digital document, execute a second MLA classifier in order to determine the document type for the digital document, wherein the second MLA classifier is associated with a second hierarchical order of execution following the first hierarchical order of execution, and wherein the second MLA classifier is trained on a second trained dataset containing no documents of the first document type.